write an essay on cloning in plants and animals

ENCYCLOPEDIC ENTRY

Cloning is a technique scientists use to create exact genetic replicas of genes, cells, or animals.

Biology, Genetics, Health, Chemistry

Cloned Beagles

Two Beagle puppies successfully cloned in Seoul, South Korea. These two dogs were cloned by a biopharmaceutical company that specializes in stem cell based therapeutics.

Photograph by Handout

Cloning is a technique scientists use to make exact genetic copies of living things. Genes , cells, tissues, and even whole animals can all be cloned .

Some clones already exist in nature. Single-celled organisms like bacteria make exact copies of themselves each time they reproduce. In humans, identical twins are similar to clones . They share almost the exact same genes . Identical twins are created when a fertilized egg splits in two.

Scientists also make clones in the lab. They often clone genes in order to study and better understand them. To clone a gene , researchers take DNA from a living creature and insert it into a carrier like bacteria or yeast. Every time that carrier reproduces, a new copy of the gene is made.

Animals are cloned in one of two ways. The first is called embryo twinning. Scientists first split an embryo in half. Those two halves are then placed in a mother’s uterus. Each part of the embryo develops into a unique animal, and the two animals share the same genes . The second method is called somatic cell nuclear transfer. Somatic cells are all the cells that make up an organism, but that are not sperm or egg cells. Sperm and egg cells contain only one set of chromosomes , and when they join during fertilization, the mother’s chromosomes merge with the father’s. Somatic cells , on the other hand, already contain two full sets of chromosomes . To make a clone , scientists transfer the DNA from an animal’s somatic cell into an egg cell that has had its nucleus and DNA removed. The egg develops into an embryo that contains the same genes as the cell donor. Then the embryo is implanted into an adult female’s uterus to grow.

In 1996, Scottish scientists cloned the first animal, a sheep they named Dolly. She was cloned using an udder cell taken from an adult sheep. Since then, scientists have cloned cows, cats, deer, horses, and rabbits. They still have not cloned a human, though. In part, this is because it is difficult to produce a viable clone . In each attempt, there can be genetic mistakes that prevent the clone from surviving. It took scientists 276 attempts to get Dolly right. There are also ethical concerns about cloning a human being.

Researchers can use clones in many ways. An embryo made by cloning can be turned into a stem cell factory. Stem cells are an early form of cells that can grow into many different types of cells and tissues. Scientists can turn them into nerve cells to fix a damaged spinal cord or insulin-making cells to treat diabetes.

The cloning of animals has been used in a number of different applications. Animals have been cloned to have gene mutations that help scientists study diseases that develop in the animals. Livestock like cows and pigs have been cloned to produce more milk or meat. Clones can even “resurrect” a beloved pet that has died. In 2001, a cat named CC was the first pet to be created through cloning. Cloning might one day bring back extinct species like the woolly mammoth or giant panda.

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Related Resources

10.1 Cloning and Genetic Engineering

Learning objectives.

• Explain the basic techniques used to manipulate genetic material
• Explain molecular and reproductive cloning

Biotechnology is the use of artificial methods to modify the genetic material of living organisms or cells to produce novel compounds or to perform new functions. Biotechnology has been used for improving livestock and crops since the beginning of agriculture through selective breeding. Since the discovery of the structure of DNA in 1953, and particularly since the development of tools and methods to manipulate DNA in the 1970s, biotechnology has become synonymous with the manipulation of organisms’ DNA at the molecular level. The primary applications of this technology are in medicine (for the production of vaccines and antibiotics) and in agriculture (for the genetic modification of crops). Biotechnology also has many industrial applications, such as fermentation, the treatment of oil spills, and the production of biofuels, as well as many household applications such as the use of enzymes in laundry detergent.

Manipulating Genetic Material

To accomplish the applications described above, biotechnologists must be able to extract, manipulate, and analyze nucleic acids.

Review of Nucleic Acid Structure

To understand the basic techniques used to work with nucleic acids, remember that nucleic acids are macromolecules made of nucleotides (a sugar, a phosphate, and a nitrogenous base). The phosphate groups on these molecules each have a net negative charge. An entire set of DNA molecules in the nucleus of eukaryotic organisms is called the genome. DNA has two complementary strands linked by hydrogen bonds between the paired bases.

Unlike DNA in eukaryotic cells, RNA molecules leave the nucleus. Messenger RNA (mRNA) is analyzed most frequently because it represents the protein-coding genes that are being expressed in the cell.

Isolation of Nucleic Acids

To study or manipulate nucleic acids, the DNA must first be extracted from cells. Various techniques are used to extract different types of DNA ( Figure 10.2 ). Most nucleic acid extraction techniques involve steps to break open the cell, and then the use of enzymatic reactions to destroy all undesired macromolecules. Cells are broken open using a detergent solution containing buffering compounds. To prevent degradation and contamination, macromolecules such as proteins and RNA are inactivated using enzymes. The DNA is then brought out of solution using alcohol. The resulting DNA, because it is made up of long polymers, forms a gelatinous mass.

RNA is studied to understand gene expression patterns in cells. RNA is naturally very unstable because enzymes that break down RNA are commonly present in nature. Some are even secreted by our own skin and are very difficult to inactivate. Similar to DNA extraction, RNA extraction involves the use of various buffers and enzymes to inactivate other macromolecules and preserve only the RNA.

Gel Electrophoresis

Because nucleic acids are negatively charged ions at neutral or alkaline pH in an aqueous environment, they can be moved by an electric field. Gel electrophoresis is a technique used to separate charged molecules on the basis of size and charge. The nucleic acids can be separated as whole chromosomes or as fragments. The nucleic acids are loaded into a slot at one end of a gel matrix, an electric current is applied, and negatively charged molecules are pulled toward the opposite end of the gel (the end with the positive electrode). Smaller molecules move through the pores in the gel faster than larger molecules; this difference in the rate of migration separates the fragments on the basis of size. The nucleic acids in a gel matrix are invisible until they are stained with a compound that allows them to be seen, such as a dye. Distinct fragments of nucleic acids appear as bands at specific distances from the top of the gel (the negative electrode end) that are based on their size ( Figure 10.3 ). A mixture of many fragments of varying sizes appear as a long smear, whereas uncut genomic DNA is usually too large to run through the gel and forms a single large band at the top of the gel.

Polymerase Chain Reaction

DNA analysis often requires focusing on one or more specific regions of the genome. It also frequently involves situations in which only one or a few copies of a DNA molecule are available for further analysis. These amounts are insufficient for most procedures, such as gel electrophoresis. Polymerase chain reaction (PCR) is a technique used to rapidly increase the number of copies of specific regions of DNA for further analyses ( Figure 10.4 ). PCR uses a special form of DNA polymerase, the enzyme that replicates DNA, and other short nucleotide sequences called primers that base pair to a specific portion of the DNA being replicated. PCR is used for many purposes in laboratories. These include: 1) the identification of the owner of a DNA sample left at a crime scene; 2) paternity analysis; 3) the comparison of small amounts of ancient DNA with modern organisms; and 4) determining the sequence of nucleotides in a specific region.

In general, cloning means the creation of a perfect replica. Typically, the word is used to describe the creation of a genetically identical copy. In biology, the re-creation of a whole organism is referred to as “reproductive cloning.” Long before attempts were made to clone an entire organism, researchers learned how to copy short stretches of DNA—a process that is referred to as molecular cloning. The technique offered methods to create new medicines and to overcome difficulties with existing ones. When Lydia Villa-Komaroff, working in the Gilbert Lab at Harvard, published the first paper outlining the technique for producing synthetic insulin, diabetes researchers and patients received new hope in fighting the disease. Insulin at that time was only produced using pig and cow pancreases, and the life-saving substance was often in short supply. Synthetic insulin, once mass produced, would solve that problem for many patients. These early discoveries led to the "BioTech Boom," and spurred continued research and funding for newer and better ways to improve health.

Molecular Cloning

Cloning allows for the creation of multiple copies of genes, expression of genes, and study of specific genes. To get the DNA fragment into a bacterial cell in a form that will be copied or expressed, the fragment is first inserted into a plasmid. A plasmid (also called a vector in this context) is a small circular DNA molecule that replicates independently of the chromosomal DNA in bacteria. In cloning, the plasmid molecules can be used to provide a "vehicle" in which to insert a desired DNA fragment. Modified plasmids are usually reintroduced into a bacterial host for replication. As the bacteria divide, they copy their own DNA (including the plasmids). The inserted DNA fragment is copied along with the rest of the bacterial DNA. In a bacterial cell, the fragment of DNA from the human genome (or another organism that is being studied) is referred to as foreign DNA to differentiate it from the DNA of the bacterium (the host DNA).

Plasmids occur naturally in bacterial populations (such as Escherichia coli ) and have genes that can contribute favorable traits to the organism, such as antibiotic resistance (the ability to be unaffected by antibiotics). Plasmids have been highly engineered as vectors for molecular cloning and for the subsequent large-scale production of important molecules, such as insulin. A valuable characteristic of plasmid vectors is the ease with which a foreign DNA fragment can be introduced. These plasmid vectors contain many short DNA sequences that can be cut with different commonly available restriction enzymes . Restriction enzymes (also called restriction endonucleases) recognize specific DNA sequences and cut them in a predictable manner; they are naturally produced by bacteria as a defense mechanism against foreign DNA. Many restriction enzymes make staggered cuts in the two strands of DNA, such that the cut ends have a 2- to 4-nucleotide single-stranded overhang. The sequence that is recognized by the restriction enzyme is a four- to eight-nucleotide sequence that is a palindrome. Like with a word palindrome, this means the sequence reads the same forward and backward. In most cases, the sequence reads the same forward on one strand and backward on the complementary strand. When a staggered cut is made in a sequence like this, the overhangs are complementary ( Figure 10.5 ).

Because these overhangs are capable of coming back together by hydrogen bonding with complementary overhangs on a piece of DNA cut with the same restriction enzyme, these are called “sticky ends.” The process of forming hydrogen bonds between complementary sequences on single strands to form double-stranded DNA is called annealing . Addition of an enzyme called DNA ligase, which takes part in DNA replication in cells, permanently joins the DNA fragments when the sticky ends come together. In this way, any DNA fragment can be spliced between the two ends of a plasmid DNA that has been cut with the same restriction enzyme ( Figure 10.6 ).

Plasmids with foreign DNA inserted into them are called recombinant DNA molecules because they contain new combinations of genetic material. Proteins that are produced from recombinant DNA molecules are called recombinant proteins . Not all recombinant plasmids are capable of expressing genes. Plasmids may also be engineered to express proteins only when stimulated by certain environmental factors, so that scientists can control the expression of the recombinant proteins.

Reproductive Cloning

Reproductive cloning is a method used to make a clone or an identical copy of an entire multicellular organism. Most multicellular organisms undergo reproduction by sexual means, which involves the contribution of DNA from two individuals (parents), making it impossible to generate an identical copy or a clone of either parent. Recent advances in biotechnology have made it possible to reproductively clone mammals in the laboratory.

Natural sexual reproduction involves the union, during fertilization, of a sperm and an egg. Each of these gametes is haploid, meaning they contain one set of chromosomes in their nuclei. The resulting cell, or zygote, is then diploid and contains two sets of chromosomes. This cell divides mitotically to produce a multicellular organism. However, the union of just any two cells cannot produce a viable zygote; there are components in the cytoplasm of the egg cell that are essential for the early development of the embryo during its first few cell divisions. Without these provisions, there would be no subsequent development. Therefore, to produce a new individual, both a diploid genetic complement and an egg cytoplasm are required. The approach to producing an artificially cloned individual is to take the egg cell of one individual and to remove the haploid nucleus. Then a diploid nucleus from a body cell of a second individual, the donor, is put into the egg cell. The egg is then stimulated to divide so that development proceeds. This sounds simple, but in fact it takes many attempts before each of the steps is completed successfully.

The first cloned agricultural animal was Dolly, a sheep who was born in 1996. The success rate of reproductive cloning at the time was very low. Dolly lived for six years and died of a lung tumor ( Figure 10.7 ). There was speculation that because the cell DNA that gave rise to Dolly came from an older individual, the age of the DNA may have affected her life expectancy. Since Dolly, several species of animals (such as horses, bulls, and goats) have been successfully cloned.

There have been attempts at producing cloned human embryos as sources of embryonic stem cells. In the procedure, the DNA from an adult human is introduced into a human egg cell, which is then stimulated to divide. The technology is similar to the technology that was used to produce Dolly, but the embryo is never implanted into a surrogate carrier. The cells produced are called embryonic stem cells because they have the capacity to develop into many different kinds of cells, such as muscle or nerve cells. The stem cells could be used to research and ultimately provide therapeutic applications, such as replacing damaged tissues. The benefit of cloning in this instance is that the cells used to regenerate new tissues would be a perfect match to the donor of the original DNA. For example, a leukemia patient would not require a sibling with a tissue match for a bone-marrow transplant. Freda Miller and Elaine Fuchs, working independently, discovered stem cells in different layers of the skin. These cells help the skin repair itself, and their discovery may have applications in treatments of skin disease and potentially other conditions, such as nerve damage.

Visual Connection

Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?

Genetic Engineering

Using recombinant DNA technology to modify an organism’s DNA to achieve desirable traits is called genetic engineering . Addition of foreign DNA in the form of recombinant DNA vectors that are generated by molecular cloning is the most common method of genetic engineering. An organism that receives the recombinant DNA is called a genetically modified organism (GMO). If the foreign DNA that is introduced comes from a different species, the host organism is called transgenic . Bacteria, plants, and animals have been genetically modified since the early 1970s for academic, medical, agricultural, and industrial purposes. These applications will be examined in more detail in the next module.

Link to Learning

Watch this short video explaining how scientists create a transgenic animal.

Although the classic methods of studying the function of genes began with a given phenotype and determined the genetic basis of that phenotype, modern techniques allow researchers to start at the DNA sequence level and ask: "What does this gene or DNA element do?" This technique, called reverse genetics , has resulted in reversing the classical genetic methodology. One example of this method is analogous to damaging a body part to determine its function. An insect that loses a wing cannot fly, which means that the wing’s function is flight. The classic genetic method compares insects that cannot fly with insects that can fly, and observes that the non-flying insects have lost wings. Similarly in a reverse genetics approach, mutating or deleting genes provides researchers with clues about gene function. Alternately, reverse genetics can be used to cause a gene to overexpress itself to determine what phenotypic effects may occur.

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• Location: Houston, Texas
• Book URL: https://openstax.org/books/concepts-biology/pages/1-introduction
• Section URL: https://openstax.org/books/concepts-biology/pages/10-1-cloning-and-genetic-engineering

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10.1: Cloning and Genetic Engineering

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Biotechnology is the use of artificial methods to modify the genetic material of living organisms or cells to produce novel compounds or to perform new functions. Biotechnology has been used for improving livestock and crops since the beginning of agriculture through selective breeding. Since the discovery of the structure of DNA in 1953, and particularly since the development of tools and methods to manipulate DNA in the 1970s, biotechnology has become synonymous with the manipulation of organisms’ DNA at the molecular level. The primary applications of this technology are in medicine (for the production of vaccines and antibiotics) and in agriculture (for the genetic modification of crops). Biotechnology also has many industrial applications, such as fermentation, the treatment of oil spills, and the production of biofuels, as well as many household applications such as the use of enzymes in laundry detergent.

Manipulating Genetic Material

To accomplish the applications described above, biotechnologists must be able to extract, manipulate, and analyze nucleic acids.

Review of Nucleic Acid Structure

To understand the basic techniques used to work with nucleic acids, remember that nucleic acids are macromolecules made of nucleotides (a sugar, a phosphate, and a nitrogenous base). The phosphate groups on these molecules each have a net negative charge. An entire set of DNA molecules in the nucleus of eukaryotic organisms is called the genome. DNA has two complementary strands linked by hydrogen bonds between the paired bases.

Unlike DNA in eukaryotic cells, RNA molecules leave the nucleus. Messenger RNA (mRNA) is analyzed most frequently because it represents the protein-coding genes that are being expressed in the cell.

Isolation of Nucleic Acids

To study or manipulate nucleic acids, the DNA must first be extracted from cells. Various techniques are used to extract different types of DNA (Figure \(\PageIndex{1}\)). Most nucleic acid extraction techniques involve steps to break open the cell, and then the use of enzymatic reactions to destroy all undesired macromolecules. Cells are broken open using a detergent solution containing buffering compounds. To prevent degradation and contamination, macromolecules such as proteins and RNA are inactivated using enzymes. The DNA is then brought out of solution using alcohol. The resulting DNA, because it is made up of long polymers, forms a gelatinous mass.

RNA is studied to understand gene expression patterns in cells. RNA is naturally very unstable because enzymes that break down RNA are commonly present in nature. Some are even secreted by our own skin and are very difficult to inactivate. Similar to DNA extraction, RNA extraction involves the use of various buffers and enzymes to inactivate other macromolecules and preserve only the RNA.

Gel Electrophoresis

Because nucleic acids are negatively charged ions at neutral or alkaline pH in an aqueous environment, they can be moved by an electric field. Gel electrophoresis is a technique used to separate charged molecules on the basis of size and charge. The nucleic acids can be separated as whole chromosomes or as fragments. The nucleic acids are loaded into a slot at one end of a gel matrix, an electric current is applied, and negatively charged molecules are pulled toward the opposite end of the gel (the end with the positive electrode). Smaller molecules move through the pores in the gel faster than larger molecules; this difference in the rate of migration separates the fragments on the basis of size. The nucleic acids in a gel matrix are invisible until they are stained with a compound that allows them to be seen, such as a dye. Distinct fragments of nucleic acids appear as bands at specific distances from the top of the gel (the negative electrode end) that are based on their size (Figure \(\PageIndex{2}\)). A mixture of many fragments of varying sizes appear as a long smear, whereas uncut genomic DNA is usually too large to run through the gel and forms a single large band at the top of the gel.

Polymerase Chain Reaction

DNA analysis often requires focusing on one or more specific regions of the genome. It also frequently involves situations in which only one or a few copies of a DNA molecule are available for further analysis. These amounts are insufficient for most procedures, such as gel electrophoresis. Polymerase chain reaction (PCR)is a technique used to rapidly increase the number of copies of specific regions of DNA for further analyses (Figure \(\PageIndex{3}\)). PCR uses a special form of DNA polymerase, the enzyme that replicates DNA, and other short nucleotide sequences called primers that base pair to a specific portion of the DNA being replicated. PCR is used for many purposes in laboratories. These include: 1) the identification of the owner of a DNA sample left at a crime scene; 2) paternity analysis; 3) the comparison of small amounts of ancient DNA with modern organisms; and 4) determining the sequence of nucleotides in a specific region.

In general, cloning means the creation of a perfect replica. Typically, the word is used to describe the creation of a genetically identical copy. In biology, the re-creation of a whole organism is referred to as “reproductive cloning.” Long before attempts were made to clone an entire organism, researchers learned how to copy short stretches of DNA—a process that is referred to as molecular cloning.

Molecular Cloning

Cloning allows for the creation of multiple copies of genes, expression of genes, and study of specific genes. To get the DNA fragment into a bacterial cell in a form that will be copied or expressed, the fragment is first inserted into a plasmid. A plasmid (also called a vector in this context) is a small circular DNA molecule that replicates independently of the chromosomal DNA in bacteria. In cloning, the plasmid molecules can be used to provide a "vehicle" in which to insert a desired DNA fragment. Modified plasmids are usually reintroduced into a bacterial host for replication. As the bacteria divide, they copy their own DNA (including the plasmids). The inserted DNA fragment is copied along with the rest of the bacterial DNA. In a bacterial cell, the fragment of DNA from the human genome (or another organism that is being studied) is referred to as foreign DNA to differentiate it from the DNA of the bacterium (the host DNA).

Plasmids occur naturally in bacterial populations (such as Escherichia coli ) and have genes that can contribute favorable traits to the organism, such as antibiotic resistance (the ability to be unaffected by antibiotics). Plasmids have been highly engineered as vectors for molecular cloning and for the subsequent large-scale production of important molecules, such as insulin. A valuable characteristic of plasmid vectors is the ease with which a foreign DNA fragment can be introduced. These plasmid vectors contain many short DNA sequences that can be cut with different commonly available restriction enzymes. Restriction enzymes (also called restriction endonucleases) recognize specific DNA sequences and cut them in a predictable manner; they are naturally produced by bacteria as a defense mechanism against foreign DNA. Many restriction enzymes make staggered cuts in the two strands of DNA, such that the cut ends have a 2- to 4-nucleotide single-stranded overhang. The sequence that is recognized by the restriction enzyme is a four- to eight-nucleotide sequence that is a palindrome. Like with a word palindrome, this means the sequence reads the same forward and backward. In most cases, the sequence reads the same forward on one strand and backward on the complementary strand. When a staggered cut is made in a sequence like this, the overhangs are complementary (Figure \(\PageIndex{4}\)).

Because these overhangs are capable of coming back together by hydrogen bonding with complementary overhangs on a piece of DNA cut with the same restriction enzyme, these are called “sticky ends.” The process of forming hydrogen bonds between complementary sequences on single strands to form double-stranded DNA is called annealing. Addition of an enzyme called DNA ligase, which takes part in DNA replication in cells, permanently joins the DNA fragments when the sticky ends come together. In this way, any DNA fragment can be spliced between the two ends of a plasmid DNA that has been cut with the same restriction enzyme (Figure \(\PageIndex{5}\)).

Plasmids with foreign DNA inserted into them are called recombinant DNA molecules because they contain new combinations of genetic material. Proteins that are produced from recombinant DNA molecules are called recombinant proteins. Not all recombinant plasmids are capable of expressing genes. Plasmids may also be engineered to express proteins only when stimulated by certain environmental factors, so that scientists can control the expression of the recombinant proteins.

Reproductive Cloning

Reproductive cloning is a method used to make a clone or an identical copy of an entire multicellular organism. Most multicellular organisms undergo reproduction by sexual means, which involves the contribution of DNA from two individuals (parents), making it impossible to generate an identical copy or a clone of either parent. Recent advances in biotechnology have made it possible to reproductively clone mammals in the laboratory.

Natural sexual reproduction involves the union, during fertilization, of a sperm and an egg. Each of these gametes is haploid, meaning they contain one set of chromosomes in their nuclei. The resulting cell, or zygote, is then diploid and contains two sets of chromosomes. This cell divides mitotically to produce a multicellular organism. However, the union of just any two cells cannot produce a viable zygote; there are components in the cytoplasm of the egg cell that are essential for the early development of the embryo during its first few cell divisions. Without these provisions, there would be no subsequent development. Therefore, to produce a new individual, both a diploid genetic complement and an egg cytoplasm are required. The approach to producing an artificially cloned individual is to take the egg cell of one individual and to remove the haploid nucleus. Then a diploid nucleus from a body cell of a second individual, the donor, is put into the egg cell. The egg is then stimulated to divide so that development proceeds. This sounds simple, but in fact it takes many attempts before each of the steps is completed successfully.

The first cloned agricultural animal was Dolly, a sheep who was born in 1996. The success rate of reproductive cloning at the time was very low. Dolly lived for six years and died of a lung tumor (Figure \(\PageIndex{6}\)). There was speculation that because the cell DNA that gave rise to Dolly came from an older individual, the age of the DNA may have affected her life expectancy. Since Dolly, several species of animals (such as horses, bulls, and goats) have been successfully cloned.

There have been attempts at producing cloned human embryos as sources of embryonic stem cells. In the procedure, the DNA from an adult human is introduced into a human egg cell, which is then stimulated to divide. The technology is similar to the technology that was used to produce Dolly, but the embryo is never implanted into a surrogate mother. The cells produced are called embryonic stem cells because they have the capacity to develop into many different kinds of cells, such as muscle or nerve cells. The stem cells could be used to research and ultimately provide therapeutic applications, such as replacing damaged tissues. The benefit of cloning in this instance is that the cells used to regenerate new tissues would be a perfect match to the donor of the original DNA. For example, a leukemia patient would not require a sibling with a tissue match for a bone-marrow transplant.

ART CONNECTION

Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?

Genetic Engineering

Using recombinant DNA technology to modify an organism’s DNA to achieve desirable traits is called genetic engineering. Addition of foreign DNA in the form of recombinant DNA vectors that are generated by molecular cloning is the most common method of genetic engineering. An organism that receives the recombinant DNA is called a genetically modified organism (GMO). If the foreign DNA that is introduced comes from a different species, the host organism is called transgenic. Bacteria, plants, and animals have been genetically modified since the early 1970s for academic, medical, agricultural, and industrial purposes. These applications will be examined in more detail in the next module.

CONCEPT IN ACTION

Watch this short video explaining how scientists create a transgenic animal.

Although the classic methods of studying the function of genes began with a given phenotype and determined the genetic basis of that phenotype, modern techniques allow researchers to start at the DNA sequence level and ask: "What does this gene or DNA element do?" This technique, called reverse genetics, has resulted in reversing the classical genetic methodology. One example of this method is analogous to damaging a body part to determine its function. An insect that loses a wing cannot fly, which means that the wing’s function is flight. The classic genetic method compares insects that cannot fly with insects that can fly, and observes that the non-flying insects have lost wings. Similarly in a reverse genetics approach, mutating or deleting genes provides researchers with clues about gene function. Alternately, reverse genetics can be used to cause a gene to overexpress itself to determine what phenotypic effects may occur.

Nucleic acids can be isolated from cells for the purposes of further analysis by breaking open the cells and enzymatically destroying all other major macromolecules. Fragmented or whole chromosomes can be separated on the basis of size by gel electrophoresis. Short stretches of DNA can be amplified by PCR. DNA can be cut (and subsequently re-spliced together) using restriction enzymes. The molecular and cellular techniques of biotechnology allow researchers to genetically engineer organisms, modifying them to achieve desirable traits.

Cloning may involve cloning small DNA fragments (molecular cloning), or cloning entire organisms (reproductive cloning). In molecular cloning with bacteria, a desired DNA fragment is inserted into a bacterial plasmid using restriction enzymes and the plasmid is taken up by a bacterium, which will then express the foreign DNA. Using other techniques, foreign genes can be inserted into eukaryotic organisms. In each case, the organisms are called transgenic organisms. In reproductive cloning, a donor nucleus is put into an enucleated egg cell, which is then stimulated to divide and develop into an organism.

In reverse genetics methods, a gene is mutated or removed in some way to identify its effect on the phenotype of the whole organism as a way to determine its function.

Art Connections

Figure \(\PageIndex{6}\): Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?

Because even though the original cell came from a Scottish Blackface sheep and the surrogate mother was a Scottish Blackface, the DNA came from a Finn-Dorset.

Contributors and Attributions

Samantha Fowler (Clayton State University), Rebecca Roush (Sandhills Community College), James Wise (Hampton University). Original content by OpenStax (CC BY 4.0; Access for free at https://cnx.org/contents/b3c1e1d2-83...4-e119a8aafbdd ).

Animal cloning

So Dolly was not the first clone, and she looked like any other sheep, so why did she cause so much excitement and concern? Because she was the first mammal to be cloned from an adult cell, rather than an embryo. This was a major scientific achievement, but also raised ethical concerns. Since 1996, when Dolly was born, other sheep have been cloned from adult cells, as have mice, rabbits, horses and donkeys, pigs, goats and cattle. In 2004 a mouse was cloned using a nucleus from an olfactory neuron, showing that the donor nucleus can come from a tissue of the body that does not normally divide.

How was Dolly produced?

Producing an animal clone from an adult cell is obviously much more complex and difficult than growing a plant from a cutting. So when scientists working at the Roslin Institute in Scotland produced Dolly, the only lamb born from 277 attempts, it was a major news story around the world. To produce Dolly, the scientists used the nucleus of an udder cell from a six-year-old Finn Dorset white sheep. The nucleus contains nearly all the cell's genes. They had to find a way to 'reprogram' the udder cells - to keep them alive but stop them growing – which they achieved by altering the growth medium (the ‘soup’ in which the cells were kept alive). Then they injected the cell into an unfertilised egg cell which had had its nucleus removed, and made the cells fuse by using electrical pulses. The unfertilised egg cell came from a Scottish Blackface ewe. When the scientists had managed to fuse the nucleus from the adult white sheep cell with the egg cell from the black-faced sheep, they needed to make sure that the resulting cell would develop into an embryo. They cultured it for six or seven days to see if it divided and  developed normally, before implanting it into a surrogate mother, another Scottish Blackface ewe. Dolly had a white face. From 277 cell fusions, 29 early embryos developed and were implanted into 13 surrogate mothers. But only one pregnancy went to full term, and the 6.6kg Finn Dorset lamb 6LLS (alias Dolly) was born after 148 days.

Why are scientists interested in cloning?

The main reason that the scientists at Roslin wanted to be able to clone sheep and other large animals was connected with their research aimed at producing medicines in the milk of such animals. Researchers have managed to transfer human genes that produce useful proteins into sheep and cows, so that they can produce, for instance, the blood clotting agent factor IX to treat haemophilia or alpha-1-antitrypsin to treat cystic fibrosis and other lung conditions. Cloned animals could also be developed that would produce human antibodies against infectious diseases and even cancers. ‘Foreign’ genes have been transplanted into zebra fish, which are widely used in laboratories, and embryos cloned from these fish express the foreign protein. If this technique can be applied to mammalian cells and the cells cultured to produce cloned animals, these could then breed conventionally to form flocks of genetically engineered animals all producing medicines in their milk. There are other medical and scientific reasons for the interest in cloning. It is already being used alongside genetic techniques in the  development of animal organs for transplant into humans (xenotransplantation). Combining such genetic techniques with cloning of pigs (achieved for the first time in March 2000) would lead to a reliable supply of suitable donor organs. The use of pig organs has been hampered by the presence of a sugar, alpha gal, on pig cells, but in 2002 scientists succeeded in knocking out the gene that makes it, and these ‘knockout’ pigs could be bred naturally. However, there are still worries about virus transmission. The study of animal clones and cloned cells could lead to greater understanding of the development of the embryo and of ageing and  age-related diseases. Cloned mice become obese, with related symptoms such as raised plasma insulin and leptin levels, though their offspring do not and are normal. Cloning could be used to create better animal models of diseases, which could in turn lead to further progress in understanding and treating those diseases. It could even enhance biodiversity by ensuring the continuation of rare breeds and endangered species.

What happened to Dolly?

Dolly, probably the most famous sheep in the world, lived a pampered existence at the Roslin Institute. She mated and produced normal offspring in the normal way, showing that such cloned animals can reproduce. Born on 5 July 1996, she was euthanased on 14 February 2003, aged six and a half. Sheep can live to age 11 or 12, but Dolly suffered from arthritis in a hind leg joint and from sheep pulmonary adenomatosis, a virus-induced lung tumour to which sheep raised indoors are prone. On 2 February 2003, Australia's first cloned sheep died unexpectedly at the age of two years and 10 months. The cause of death was unknown and the carcass was quickly cremated as it was decomposing. Dolly’s chromosomes were are a little shorter than those of other sheep, but in most other ways she was the same as any other sheep of her chronological age. However, her early ageing may reflect that she was raised from the nucleus of a 6-year old sheep. Study of her cells also revealed that the very small amount of DNA outside the nucleus, in the mitochondria of the cells, is all inherited from the donor egg cell, not from the donor nucleus like the rest of her DNA. So she is not a completely identical copy. This finding could be important for sex-linked diseases such as haemophilia, and certain neuromuscular, brain and kidney conditions that are passed on through the mother's side of the family only.

Improving the technology

Scientists are working on ways to improve the technology. For example, when two genetically identical cloned mice embryos are combined, the aggregate embryo is more likely to survive to birth. Improvements in the culture medium may also help.

Ethical concerns and regulation

Most of the ethical concerns about cloning relate to the possibility that it might be used to clone humans. There would be enormous technical difficulties. As the technology stands at present, it would have to involve women willing to donate perhaps hundreds of eggs, surrogate pregnancies with high rates of miscarriage and stillbirth, and the possibility of premature ageing and high cancer rates for any children so produced. However, in 2004 South Korean scientists announced that they had cloned 30 human embryos, grown them in the laboratory until they were a hollow ball of cells, and produced a line of stem cells from them. Further ethical discussion was raised in 2008 when scientists succeeded in cloning mice from tissue that had been frozen for 16 years. In the USA, President Clinton asked the National Bioethics Commission and Congress to examine the issues, and in the UK the House of Commons Science and Technology Committee, the Human Embryology and Fertilisation Authority and the Human Genetics Advisory Commission all consulted widely and advised that human cloning should be banned. The Council of Europe has banned human cloning: in fact most countries have banned the use of cloning to produce human babies (human reproductive cloning). However, there is one important medical aspect of cloning technology that could be applied to humans, which people may find less objectionable. This is therapeutic cloning (or cell nucleus replacement) for tissue engineering, in which tissues, rather than a baby, are created. In therapeutic cloning, single cells would be taken from a person and 'reprogrammed' to create stem cells, which have the potential to  develop into any type of cell in the body. When needed, the stem cells could be thawed and then induced to grow into particular types of cell such as heart, liver or brain cells that could be used in medical treatment. Reprogramming cells is likely to prove technically difficult. Therapeutic cloning research is already being conducted in animals, and stem cells have been grown by this method and transplanted back into the original donor animal. In humans, this technique would revolutionise cell and tissue transplantation as a method of treating diseases. However, it is a very new science and has raised ethical concerns. In the UK a group headed by the Chief Medical Officer, Professor Liam Donaldson, has recommended that research on early human embryos should be allowed. The Human Fertilisation and Embryology Act was amended in 2001 to allow the use of embryos for stem cell research and consequently the HFEA has the responsibility for regulating all embryonic stem cell research in the UK. There is a potential supply of early embryos as patients undergoing in-vitro fertilisation usually produce a surplus of fertilised eggs. As far as animal cloning is concerned, all cloning for research or medical purposes in the UK must be approved by the Home Office under the strict controls of the Animals (Scientific Procedures) Act 1986 . This safeguards animal welfare while allowing important scientific and medical research to go ahead.

Further information

The Roslin Institute has lots of information about the research that led to Dolly, and the scientific studies of Dolly, as well as links to many other sites that provide useful information on the scientific and ethical aspects of this research. The report of the Chief Medical Officer's Expert Advisory Group on Therapeutic Cloning: Stem cell research: medical progress with responsibility is available from the UK Department of Health , PO Box 777, London SE1 6XH. Further information on therapeutic cloning and stem cell research is available from the Medical Research Council . Interesting illustrated features on cloning have been published by Time , New Scientist . BBC News Online has a Q&A What is Cloning?   IMAGE © THE ROSLIN INSTITUTE

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• Why We’re Unique

Growing plants and animals by cloning

Introduction: (initial observation).

Cloning is the process of making a genetically identical organism through nonsexual means.

A cloned organism has the same physical and biological properties as its parent. For example, if a black sheep is resistant to certain disease. It’s clone will also be black and will be resistant to the same disease.

About the image: Rodent genome modification methods are being developed at Advanced Cell Technology by their inventors, Dr. Teruhiko Wakayama and Tony Perry. The mice on the image contain the gene for a green fluorescent protein, put there by a novel method called metaphase II transgenesis. This means that they glow green under ‘black light’ (long-wavelength UV) light. But producing green mice is just the first step using an easily identified marker gene; more importantly, the method can be used to introduce genes to study disease and produce more effective medicines. The cloning and transgenesis methods pioneered by Drs. Wakayama and Perry will help ACT to achieve this more quickly.

In this project you will study about different methods of cloning and experiment cloning a plant and an animal.

This project guide contains information that you need in order to start your project. If you have any questions or need more support about this project, click on the “ Ask Question ” button on the top of this page to send me a message.

If you are new in doing science project, click on “ How to Start ” in the main page. There you will find helpful links that describe different types of science projects, scientific method, variables, hypothesis, graph, abstract and all other general basics that you need to know.  

Project advisor

Information Gathering:

Find out about cells, nuclei, chromosomes and genes. Read books, magazines or ask professionals who might know in order to learn about creation of clones in nature. Study about different methods of cloning. Keep track of where you got your information from.

The following are samples of the information that you may gather:

Cloning is the process of making a genetically identical organism through nonsexual means. It has been used for many years to produce plants (even growing a plant from a cutting is a type of cloning). Animal cloning has been the subject of scientific experiments for years, but garnered little attention until the birth of the first cloned mammal in 1997, a sheep named Dolly. Since Dolly , several scientists have cloned other animals, including cows and mice. The recent success in cloning animals has sparked fierce debates among scientists, politicians and the general public about the use and morality of cloning plants, animals and possibly humans.

Cloning in Nature

Cloning has been going on in the natural world for thousands of years. A clone is simply one living thing made from another, leading to two organisms with the same set of genes. In that sense, identical twins are clones, because they have identical DNA. Sometimes, plants are self-pollinated, producing seeds and eventually more plants with the same genetic code. Some forests are made entirely of trees originating from one single plant; the original tree spread its roots, which later sprouted new trees. When flatworms, such as liver flukes, are cut in half, they regenerate the missing parts of their bodies, leading to two worms with the same set of genes. However, the ability to intentionally create a clone in the animal kingdom by working on the cellular level is a very recent development.

Nature has been cloning organisms for billions of years. For example, when a strawberry plant sends out a runner (a form of modified stem), a new plant grows where the runner takes root. That new plant is a clone. Similar cloning occurs in grass, potatoes and onions.

People have been cloning plants in one way or another for thousands of years. For example, when you take a leaf cutting from a plant and grow it into a new plant ( vegetative propagation ), you are cloning the original plant because the new plant has the same genetic makeup as the donor plant. Vegetative propagation works because the end of the cutting forms a mass of non-specialized cells called a callus. With luck, the callus will grow, divide and form various specialized cells (roots, stems), eventually forming a new plant.

Sexual reproduction involves the merging of two sets of DNA (one from the father’s sperm and one from the mother’s egg) to produce a new offspring that is genetically different from either parent. Asexual reproduction (without sex) produces offspring that are genetically identical to the single parent organism.

More recently, scientists have been able to clone plants by taking pieces of specialized roots, breaking them up into root cells and growing the root cells in a nutrient-rich culture. In culture, the specialized cells become unspecialized ( dedifferentiated ) into calluses. The calluses can then be stimulated with the appropriate plant hormones to grow into new plants that are identical to the original plant from which the root pieces were taken.

This procedure, called tissue culture propagation , has been widely used by horticulturists to grow prized orchids and other rare flowers.

Plants are not the only organisms that can be cloned naturally. The unfertilized eggs of some animals (small invertebrates, worms, some species of fish, lizards and frogs) can develop into full-grown adults under certain environmental conditions — usually a chemical stimulus of some kind. This process is called parthenogenesis , and the offspring are clones of the females that laid the eggs.

Another example of natural cloning is identical twins . Although they are genetically different from their parents, identical twins are naturally occurring clones of each other.

Scientists have experimented with animal cloning, but have never been able to stimulate a specialized (differentiated) cell to produce a new organism directly. Instead, they rely on transplanting the genetic information from a specialized cell into an unfertilized egg cell whose genetic information has been destroyed or physically removed.

The History of Cloning

Information Source: New York Times, 3 March 1997, pp. A20-22 .

The Three Types of Cloning:

Embryo cloning: This is a medical technique which produces monozygotic (identical) twins or triplets. It duplicates the process that nature uses to produce twins or triplets. One or more cells are removed from a fertilized embryo and encouraged to develop into one or more duplicate embryos. Twins or triplets are thus formed, with identical DNA. This has been done for many years on various species of animals; only very limited experimentation has been done on humans.

Adult DNA cloning

(a.k.a. reproductive cloning)

This technique which is intended to produce a duplicate of an existing animal. It has been used to clone a sheep and other mammals. The DNA from an ovum is removed and replaced with the DNA from a cell removed from an adult animal. Then, the fertilized ovum, now called a pre-embryo, is implanted in a womb and allowed to develop into a new animal. As of 2002-JAN, It had not been tried on humans. It is specifically forbidden by law in many countries. There are rumors that Dr. Severino Aninori has successfully initiated a pregnancy through reproductive cloning. It has the potential of producing a twin of an existing person. Based on previous animal studies, it also has the potential of producing severe genetic defects. For the latter reason alone, many medical ethicists consider it to be a profoundly immoral procedure when done on humans.

Therapeutic cloning (a.k.a. biomedical cloning): This is a procedure whose initial stages are identical to adult DNA cloning. However, the stem cells are removed from the pre-embryo with the intent of producing tissue or a whole organ for transplant back into the person who supplied the DNA. The pre-embryo dies in the process. The goal of therapeutic cloning is to produce a healthy copy of a sick person’s tissue or organ for transplant. This technique would be vastly superior to relying on organ transplants from other people. The supply would be unlimited, so there would be no waiting lists. The tissue or organ would have the sick person’s original DNA; the patient would not have to take immunosuppressant drugs for the rest of their life, as is now required after transplants. There would not be any danger of organ rejection.

CLONING PLANTS

ASEXUAL PROPAGATION OF PLANTS IS A FORM OF CLONING

Asexual propagation does not involve exchange of genetic material, so it almost always produces plants that are identical to a single parent. Delicious apple and Bartlett pear are two examples of species that have been asexually propagated for decades. Asexual propagation methods include cuttings, layering, division, grafting, budding and tissue culture.

Cuttings involve removing a piece from the parent plant and that piece then regrows the lost parts or tissues. Both woody and herbaceous plants are asexually propagated by cuttings of stems, leaves and roots. New plants can be grown from parts of plants because each living plant cell contains the ability to duplicate all plant parts and functions. Mature cells can change into MERISTEMATIC (mare-ah-ste-MAT-ick) cells that are found at rapid growth sites like buds.

There are many types of cuttings. Often, a plant can be propagated by more than one method of cutting. Some plants will reproduce readily from cuttings and others take a considerable amount of time and care.

STOCK PLANTS are the parent plants used in asexual propagation. Stock plants must be in excellent health and should possess characteristics desirable for production of new plants. Herbaceous cuttings are those taken from nonwoody plants, such as perennials and houseplants.

Softwood cuttings are pieces of new growth taken from woody stock plants. These cuttings must be taken before the new growth starts to harden. Hardwood cuttings are taken from tissue which has become woody. Other forms of cuttings are leaf cuttings and root cuttings.

The gardener must try to duplicate the conditions needed for a plant to root from a cutting. High humidity, indirect light and soil temperatures of 70 to 80 degrees F are best for most cuttings. These conditions may be created by keeping cuttings enclosed under glass or in plastic bags in dappled shade. Cuttings must be shielded from direct sunlight, especially if they are under glass or plastic.

STEM CUTTINGS

When a cutting is made, injured xylem and phloem cells plug the tubes so that precious fluids are not lost. Usually a CALLUS forms at the cut. Cells near the callus area reorganize to form adventitious roots.

Stem cuttings are the most commonly used method to produce houseplants. Select vigorous, new growth with no flower buds. Stem sections should be free of diseases and insects. Each cutting should be 2 to 4 inches long and have 2 or 3 leaves attached.

Make a cut 1/4 inch below a leaf node and pull off the leaves that are at the nodes that will be below the surface of the rooting medium. ROOTING HORMONE helps to stimulate rooting, but is optional. Pour a small amount of the rooting hormone into a clean container to prevent contamination of all of your rooting hormone. Dip the base of the stem, including the node area, into the rooting powder. The stem should be dry when dipped.

Commercial rooting products often include a fungicide. This is a good idea given the damp conditions required for rooting success. Tap off excess powder, since too much hormone can inhibit rooting.

Poke a hole in the medium before inserting the cutting to avoid loss of the rooting hormone. Insert treated cutting in a moist rooting medium. A suitable rooting medium is half perlite and half sphagnum peat moss. Any disinfested container with drainage is acceptable for use.

Cover container and cutting with a plastic bag tent to maintain high humidity. Place unit in a warm area with indirect light. Check the rooting medium every few days to make sure it remains moist. Rooting can take from a few days up to several months.

After a few weeks, test for rooting by gently tugging at the cutting. If there is resistance, rooting has started and the plastic cover may be removed. More detailed instructions on stem cuttings are provided in Fact Sheet 1226, Reference Prop.1.

LEAF CUTTINGS

In this method, a leaf blade or leaf with petiole is used to propagate new plants. The same steps are followed as for stem cuttings. Choose a healthy leaf from a vigorously growing plant. Cut it close to the stem with a sharp, disinfested razor or knife. Trim off 1/4 of the leaf and dip into rooting hormone, if desired. Insert the leaf into rooting medium so that 1/3 of the leaf is below the surface.

One or many new small plants form at the base of the leaf. African violet leaves will produce many new plants. Begonia leaves can be divided into segments for propagation; however each leaf piece must contain a major vein. With leaf cuttings, the original leaf is not a part of the new plant and is usually discarded.

Many succulent plants, such as sedum, jade, and peperomia, can be propagated by leaf cutting. Some plants such as Kalanchoe pinnata or K. bryophyllum, piggy-back or air plants, form their own new plantlets in this fashion.

ROOT CUTTINGS

Cultivation of root cuttings probably started after gardeners observed new plants growing from pieces of root accidentally left behind in the soil. Take cuttings from newer root growth. Make cuttings 1 to 4 inches long from roots that are 1/4 to 1/2 inch in diameter. Be sure that the roots collected are from the chosen plant and not neighboring plants.

Cuttings should be taken during the dormant season when roots have large carbohydrate supplies. However, they also may be taken throughout the growing season. Cut straight through the end of the root closest to the stem. Cut the other end on a slant. This allows you to remember which end is the top (the straight cut) and which is the bottom (the diagonal cut).

Store cuttings from dormant roots for 3 weeks in moist rooting medium at 40 degrees F. Remove from storage and plant upright in the growing medium. Keep moist and warm, in a bright location until growth and weather permit acclimatizing to the outdoors.

If root cuttings are taken during active growth, skip the storage period and place cuttings directly in the rooting medium. For smaller plants, take 1- to 2-inch sections. Place cuttings horizontally a half inch below the surface of the rooting medium. These cuttings should be handled indoors or in a HOTBED. The fine roots of many perennials are used for propagation. Root cuttings of some variegated plants will lose their variegation.

MICROPROPAGATION OR TISSUE CULTURE

Each plant cell has the potential to grow into a new plant exactly like the parent. This fact coupled with technical advances, specialized equipment and sterile laboratory conditions has produced modern tissue culture.

In tissue culture, individual or small groups of plant cells are manipulated so they each produce a new plant. A tiny piece of bud, leaf or stem can produce incredible numbers of new plants in a small space in a short time.

The advantages of tissue culture, in addition to speed and efficiency of propagation, include production of disease-free plants. New plants can be made available to the public more quickly because of tissue culture.

However, there are some problems with spontaneous mutations which naturally occur. In tissue culture, the incidence of these mutations is greatly increased.

Conditions for tissue culture are very exacting. Absolutely sterile conditions must be maintained. Temperature, light, humidity and atmosphere are strictly controlled with electronic sensors and computerized controls.

Question/ Purpose:

What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.

The purpose of this project is to understand and display different methods of cloning.

You may choose to change this project from a display project to an experimental project. Some of the questions that I propose for your experimental project are:

• What is the best temperature for cloning flatworms by cutting?
• What invertebrates can be cloned by cutting? (Test at least 3 different invertebrates).
• What plants can be cloned and propagated by stem cutting?

If you have access to high quality microscopes and laboratory equipment, you may choose to do more complex (College level) experiments. The following are some sample questions:

• What are the best conditions for cell starvation? (As you know, cell starvation substitutes removal of nucleus from an egg cell. In this method nucleus shrinks and disappears by starvation.)
• What is the best voltage for cell fusion?

Identify Variables:

When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.

A display project does not need variables! If you do this project as an experimental project, you will then need to define variables. For example imagine your question is: What is the best temperature for cloning flatworms by cutting?

In this case you define variables as follows:

Independent variable is temperature. Dependent variable is the rate of success in regeneration of new flatworms from flatworm pieces. Controlled variables are the type of flatworm, the size and orientation of pieces and experiment procedures.

Hypothesis:

Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.

A display project does not need a hypothesis, however if you are doing this as an experimental project, the following is a sample hypothesis:

The rate of regeneration of flatworm from pieces will be maximized at warm temperatures (85ºF). My hypothesis is based on my gathered information and an online document suggesting to lower the temperature in an aquarium to prevent regeneration of flatworms.

Experiment Design:

Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”

Experiment 1: Cloning Flatworms (Planarian)

Flatworms can be found in many different sizes and shapes. They can be as small as a few millimeters up to 60-70 millimeters. If you choose to do this experiment, you need to find and catch your own flatworms. I don’t know of any place who may sell these animals.

If you live in an area with no access to shallow lakes or streams, you may try a similar experiment on other invertebrates such as jellyfish and sponges that can be purchased from some pet shops and aquarium stores.

Most flatworms are plain; however, some flatworms have fantastic colors.

To catch flatworms you need to know where they live and how they look.

Flatworms like to lurk in dark places in waterways.

As their name suggests, they are wormlike and flat without segments on their body. They have soft skin with hair, generally down the side. The smaller species of Flatworm wave their hair to propel themselves! The larger species move across the bottom of a waterway in a gliding fashion, helped by muscular waves that ripple down their body, but cannot swim.

Flatworms are found in streams and shallow parts of lakes. They live in dark places on the surface of rocks and plants.

What they eat:

Flatworms are mostly carnivorous and prey on invertebrates small enough to be captured. They also scavenge on the dead bodies of animals that sink to the bottom. Flatworms tend to live where there are lots of dead plant and animal remains to feed on. This means that sites of organic pollution are good for Flatworms.

How to catch it?

They creep and crawl on the coral reef and under rocks. If you want to catch a flatworm to look at, you have to pick up a rock and drop water on the worm. It will slowly get washed off. If you try to pull it off the rock, it will rip. A flatworm is as thick as folder paper. Some of them move fast and some of them move very slow. Flatworms do not move by themselves they have these little little hairs called cilia that help it to slide along with on this mucus from the worm. People are dangerous to them because sometimes they rip them off and they can be torn into pieces easily. Some are very clear, they camouflage themselves really well. Many people think that Flatworms are Nudibranchs. A Nudibranch is a Seaslug and a Flatworm comes from the family group called the Platyhelminthes. They are in a different worm group because they are not Annelids which means that they are not segmented.

It is possible to trap the flatworms by placing bin-bags of compost around and collecting any worms which congregate underneath.

Obtaining and feeding flatworms

Look for flatworms on the underside of submerged logs or stones in a pond or lake. The brown type (Dugesia) or the larger Planaria species are best for study. Trap them by wrapping a raw liver in cloth, tying with string and putting it in a pond. Leave it overnight. Flatworms congregate underneath (away from the light). In your lab, transfer the flatworms with a large medicine dropper into a bowl. Keep the containers covered with a lid when not observing. Feed finely chopped liver, hard boiled egg, or bits of worm once a week. After 3 hours remove excess food with a medicine dropper.

Note: Sometimes flatworms appear in aquariums as a pests.

When your flatworm is ready for experiment, perform the experiment. Note that the experiment of Planarian Regeneration has been performed by Harriet Randolph, professor of Biology at Bryn Mawr College.

Safety Notes: Some species of flatworm and some species of jellyfish are poisonous. Do not touch them while doing such experiments. Wear latex gloves if necessary.

Use a sterile surgery blade or utility knife to cut (transversely) a flatworm into three pieces. (If your knife is not sterile, insert it it ethyl alcohol for a few minutes or hold it in flame a few seconds).

Place all three pieces back in water and make daily observations for up to 15 days. Record your observations to show the progress of regeneration.

To make sure that your cloning experiment will be successful, you may better do this experiment simultaneously on more than one flatworm. Just make sure that you keep the pieces of each flatworm in a separate container. When pieces of each flatworm regenerate and become a new flatworm, they will all be clones of the original flatworm and they will all be genetically identical.

Varieties and extended results:

Below, several of the figures from Randolph’s manuscript are presented to illustrate the variety of ways in which she cut planarians (Planaria maculata) to challenge their regeneration abilities.

Animals were cut transversely (Fig. 1) and longitudinally (Fig. 2) and in most cases, each of the obtained pieces was capable of regenerating the missing halves.

In Fig. 4, the animals were cut both transversely and longitudinally. Randolph repeated this experiment several times and reported that ” in all cases each piece lived. Regeneration of all the missing parts took place…”

In Fig. 5, the animals were cut transversely into eight different fragments and ” all the missing parts were regenerated. The new individuals lived and seemed entirely normal…”

The experiment shown in Fig. 6 was designed to test the size limitations of planarian regeneration. As Randolph reported ” a piece only large enough to be seen with the naked eye will develop into a perfect whole”.

Later T. H. Morgan would show that a fragment 1/279th the size of the original organism is competent to regenerate a whole animal, thus confirming and extending Randolph’s results.

Planaria culture can be purchased from Home Training Tools website or from http://wardsci.com/default.asp.

Experiment 2: Cloning Plants by stem cutting

Introduction:

There are several advantages to propagating plants by cloning (root cutting, stem cutting, layering, …):

1. The new plant will be identical to the parent plant. For example, if the parent plant has multi-color foliage, the new plant grown from the cutting will have the same foliage. If the parent plant is female, the new plant will also be female. Propagating a plant by cloning will allow you to keep the special characteristics of that plant. Plants grown from seed will often be different from the parent plant and from each other.

2. Propagating a new plant via cloning avoids the difficulties of propagating by seed. For example, by using cuttings you could propagate a young tree that has not yet flowered (and thus has not yet produced seed), a male tree, or a sterile plant such as a navel orange. Additionally, some seeds are difficult to germinate, taking two to three years for the seedling to appear.

3. A new plant grown by from a cutting, layering or other methods of cloning will frequently mature faster and flower sooner than a plant grown from a seed.

Cuttings can be made from any part of the plant. Most frequently, however, either a stem or leaf is used. A stem cutting includes a piece of stem plus any attached leaves or buds. Thus, the stem cutting only needs to form new roots to be a complete, independent plant. A leaf cutting uses just the leaf, so both new roots and new stems must be formed to create a new plant.

Select a healthy garden flowers or houseplant such as Pothos for this experiment.

1. Cut off a piece of stem, 3-8 inches long. There should be at least three sets of leaves on the cutting.

2. Trim the cutting in the following way:

a. Make the bottom cut just below a node (a node is where the leaf and/or the bud joins the stem).

b. Remove 1/2 to 2/3 of the leaves, starting from the bottom of the cutting. Cut large leaves in half.

c. Remove all flowers, flower buds, and fruits if any.

3. (optional) Dip the lower inch of the cutting in rooting hormone.

4. In a pot of damp, but drained, rooting mix, make a hole for the cutting using a pencil. Put the cutting in the hole and firm the rooting mix around it. If any leaves are touching the surface of the mix, trim them back. Several cuttings can be placed in the same pot as long as their leaves do not touch.

5. Enclose the pot in a plastic bag, making sure the bag does not touch the leaves.

(Insert straws or wooden sticks around the edge of the pot to hold the bag away from the cutting. Place the pot in a bright area, but out of direct sunlight, so the leaves will receive the light they need but the plant will not get overly hot. The plastic bag insures that humidity around the leaves remains high, which slows the rate of water loss.)

6. Place the pot in a warm, bright spot but out of direct sunlight. Every few days, check the rooting mix to make sure it is damp, and water as necessary. Discard any water that collects in the bottom of the bag.

7. After two or three weeks, check to see if roots have formed by working your hand under the cutting and gently lifting (Figure 3). If no roots have formed, or if they are very small, firm the cutting back into the mix, rebag, and check for roots again in one to two weeks.

8. Once roots have formed, slowly decrease the humidity around the plant by untying the plastic bag and then opening it a little more each day. When it is growing well without a plastic bag, pot in a good quality potting mix and move to its permanent location.

Checklist for a successful experiment:

Start with cuttings that contain as much water as possible. Water the plant well the day before and take the cutting before the heat of the day reduces water content.

Once the cutting is harvested, excessive water loss must be prevented. To minimize water loss:

1. Process the cutting immediately. If this is not possible, stand the cut end in water or place the cutting in a plastic bag with a damp paper towel and store out of direct sun. If the plant is frost-tolerant, store the bagged cutting in the refrigerator.

2. Remove some of the leaves. Most of the water will be lost through the leaves, so by decreasing the leaf surface you also decrease the amount of water loss. A general rule of thumb is to remove 1/2 to 2/3 of the leaves. Cut remaining leaves in half if they are large.

Preventing Disease

Take cuttings only from healthy plants. To prevent the spread of disease, use clean tools and pots (clean with 10% bleach, rinse, and let dry thoroughly). Use fresh soilless potting mix since garden soil can harbor plant diseases.

Encouraging Root Formation

Just like leaves, the roots of plants need air to live. Rooting mix that is continuously waterlogged is devoid of air and cuttings will rot rather than form roots. A mixture of 50% vermiculite/50% perlite holds sufficient air and water to support good root growth, but any well-drained soilless potting mix is acceptable. If your cuttings frequently rot before they root, you know the mix is staying too wet. Add vermiculite or perlite to increase its air- holding capacity.

Cuttings use energy to form new roots. If the cutting has leaves, most of the energy comes from photosynthesis. Expose these cuttings to bright light, but not direct sunlight, during the rooting period. If you use hardwood cuttings that have no leaves, the energy will come from reserves stored in the woody stem. For best results, select shoots that are robust for the species. Since you want all the energy to go into the new roots, make sure you cut off any flowers or fruits that would compete for energy.

Auxin, a naturally occurring plant hormone, stimulates root formation. Several synthetic forms of auxin are sold as “rooting hormone.” Though some plants will root readily without treatment, application of rooting hormone to the base of the cutting will often improve your chance for success. Two synthetic auxins, IBA (indolebutyric acid) and NAA (naphthaleneacetic acid) are most frequently used. They are available in several concentrations and in both liquid and powder form. 1,000 ppm (0.1%) is used most often for herbaceous and softwood cuttings; 3,000 ppm (0.3%) and 8,000 ppm (0.8%) are used for semi-hardwood and hardwood cuttings. Liquid formulations can be used at low or high concentration for softwood or hardwood cuttings, respectively. To determine the appropriate concentration for your cutting, follow the instructions on the product label and the general guidelines just given, or consult the references listed at the end of this publication.

To use rooting hormone, place the amount needed in a separate container. Any material that remains after treating the cuttings should be discarded, not returned to the original container. These precautions will prevent contamination of the entire bottle of rooting hormone.

Cuttings will root more quickly and reliably in warm rooting mix. Keep your cuttings between 65°F and 75°F, avoiding excessive heat. If your area is too cold, consider a heating mat or cable especially designed for this purpose.

Experiment 3: Cloning plant by Root Cuttings

Introduction: Root cuttings probably started after gardeners observed

new plants growing from pieces of root accidentally left behind in the soil. Cuttings taken from roots may be used to clone and propagate some plants. Cuttings are usually taken when the plant is dormant and the roots contain the most stored energy. Each root produces two to three new stems and each stem then produces its own roots. The original root cutting disintegrates. Best results from root cuttings are likely if cuttings are taken in late winter or early spring. Geraniums, Blackberries, Raspberries, phlox, baby’s breath, oriental poppy and many other plants can be propagated by root cuttings; however, in this experiment we clone and propagate potato by root cutting.

Cut a healthy fresh potato into about one ounce pieces with an eye and/or bud on each piece. Plant potato pieces three to four inches deep in the soil. Water as needed to keep the soil moist (not wet). In a good season, they should sprout and grow roots in a matter of days.

Cuttings use energy to form new roots. If the cutting has leaves, most of the energy comes from photosynthesis. Expose these cuttings to bright light, but not direct sunlight, during the rooting period.

Experiment 4: Make a display to show cloning animals by DNA cloning (Nucleus transfer)

Many diagrams for animal cloning can be found on the Internet. Use them to get an idea and then make your own diagram or display. The following are some of the samples:

http://www.txtwriter.com/Backgrounders/Cloning/Cloningpage1.html

http://static.howstuffworks.com/gif/cloning-frog.gif

http://static.howstuffworks.com/gif/cloning-sheep.gif

Materials and Equipment:

List of material depends on the experiments that you choose to do. Such a list can be extracted from the experiment section.

Planaria culture can be purchased from Home Training Tools website or from http://wardsci.com/default.asp .

Calculations:

No calculation is required for this project as a display project.

Summary of Results:

Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.

It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.

Conclusion:

Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.

Related Questions & Answers:

What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.

Possible Errors:

If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.

If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.

References:

List of References

List of plants and their propagation method

http://home.hawaii.rr.com/johns/index.html

http://www.ntu.edu.au/faculties/science/sbes/sbi106/SBI106Inverts1/sld001.htm

http://cloning.tripod.com/intro.htm

http://www.religioustolerance.org/cloning.htm

http://www.ornl.gov/TechResources/Human_Genome/elsi/cloning.html#whatis

http://science.howstuffworks.com/cloning1.htm

http://planaria.neuro.utah.edu/sanchezsite/Randolph.htm

Don’t kill your plants

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Science Project

The Pros and Cons of Animal Cloning

In 1996, a pair of scientists at the Roslin Institute at the University of Edinburgh embarked on an audacious venture. Taking the somatic cell from a 6-year-old Finn-Dorset ewe, biologists Dr. Keith Campbell and Sir Ian Wilmut inserted it in the ovum harvested from another sheep. After 276 attempts, an embryo was successfully seeded, then placed inside a third female sheep, where it underwent the gestation period typical of any normal pregnancy. 

On July 5, 1996, scientists’ bold undertaking became a roaring success when “ Dolly the Sheep ,” the first successfully cloned mammal, was born. 

Called the “ world’s most famous sheep ,” Dolly lived with her human creators at the Roslin Institute. Bred with a Welsh Mountain Ram, Dolly would produce six lambs before finally being euthanized at 6.5 years old due to progressive lung disease and severe arthritis. Dolly’s taxidermied remains are now on display at the National Museum of Scotland . 

Fast forward twenty-five years. Not wanting to be outdone by NASA’s successful landing of the Perseverance Rover on Mars , on February 18, 2021, officials with the U.S. Fish and Wildlife Service announced they had successfully cloned the first U.S. endangered species, a black-footed ferret named Elizabeth Ann. 

Looking at the photos released by Fish and Wildlife , with her adorable black eye markings resembling a robber’s mask, I had to fight the sudden urge to don a loincloth and fight an evil wizard army with Elizabeth Ann as my ever loyal side-kick, à la Beastmaster-style. However, there is one eerie difference between Elizabeth Ann the ferret and Dolly the Sheep.

Unlike Dolly, who technically had three living “mothers,” Elizabeth Ann was created using extracted cells from a black-footed ferret that had died 33 years prior. 

Born December 10, 2020, Elizabeth Ann is a genetic copy of a ferret named Willa, who died in 1988. At the time of her death, DNA technology was just in its infancy. Yet, astute (or mad) scientists froze the endangered ferret’s body, where it lay in cryogenic impassiveness, waiting until the day Willa could be “reborn.” 

Those who are already a bit squeamish with the 18 different mammal species geneticists have cloned in the past 20 years – including Mice, Pigs, Cattle, Cats, Rats, Mules, Horses, Dogs, Wolf, Water Buffalo, Goats, Camel, and even monkeys – scientist’s necromancy with Elizabeth Ann the ferret is likely pretty alarming. 

In hopes of gaining a better understanding of what feels like machiavellian-science, The Debrief takes a look at some of the pros and cons of animal cloning. 

The Pros and Cons of Animal Cloning 

It’s important to note up-front, the process of reproducing by sharing virtually identical DNA sequences does occur naturally. Living in clonal colonies, plants, fungi, and single-celled organisms, such as bacteria, have been reproducing asexually for hundreds of millions of years. 

Contrary to how it may look, recent research published in the journal of Nature Genetics shows that monozygotic or “identical” twins are not clones. After sequencing DNA from 387 pairs of identical twins, scientists found that mutations during early gestation create genetic differences in identical twins. On average, identical twins have 5.2 early genetic differences between each other. 

To examine some of the pros and cons of animal cloning, the term “cloning” here doesn’t refer to natural asexual reproduction or colloquialism. Instead, “cloning” refers to the method of artificial replication of identical cells, or DNA fragments, used to create a life that would otherwise reproduce sexually. 

Maintaining Ecological Balance and Saving Endangered Species 

Two decades ago, Yellowstone National Park was in a state of ecological crisis. 

Expansion of agriculture, the decimation of the American bison population, and government predator control programs had all but wiped out the Grey Wolf in the continental United States. With the apex predator on the brink of extinction, deer and elk populations dramatically increased, resulting in overgrazing. With deer and elk gobbling up vegetation important to soil and riverbank structure with impunity, the landscape became highly vulnerable to erosion. 

Recognizing the national park’s ecosystem’s elasticity was on the brink of collapse, in 1995, conservationists reintroduced the grey wolf   to Yellowstone, and suddenly everything changed. 

As a top predator, conservationists discovered wolves were one of the significant linchpins holding together the balance between predator and prey in Yellowstone’s ecosystem. Removal of the wolves had disrupted the food chain causing something called a  trophic cascade . 

Without facing the threat of a natural predator, deer and elk populations had multiplied to the point where they were consuming more foliage than the habitat could sustain. Consequently, the reintroduction of grey wolves to Yellowstone reduced the population numbers and changed their preys’ behavior. 

Deer and elk began avoiding the valleys and gorges at Yellowstone, where the wolves could easily hunt them. In turn, thanks to the revived food source of vegetation, these areas began to flourish with species such as birds, beavers, mice, foxes, and bears. The thriving plant life along the riverbanks caused erosion to decrease significantly.

Lessons learned from Yellowstone were that even the loss of just one species could have a cascading and catastrophic effect on an entire habitat and the environment. 

Given the devastating positive or negative effect just one species can have, consider for some, cloning is very literally the only way we might be able to save them from extinction. Take, for example, the white rhinoceros.

The world’s  last known male white rhinoceros named Sudan died  in Kenya in March of 2018. The only two confirmed white rhinos left are two females, Fau, 18, and Najin, 29, living in captivity in Kenya’s Ol Pejeta Conservancy. 

Without a male rhino to mate with, when Fau and Najin finally pass away, their entire species die with them. In hopes of preventing this demise, researchers have successfully taken frozen sperm extracted from two male rhinos after their deaths and inseminated it into eggs harvested from Fatu and Najin. As of 2020, three white rhino embryos have been generated, kept frozen until they can be placed in a surrogate female. 

As was demonstrated in the case of Dolly, cloned animals can still reproduce naturally to produce offspring. So the goal of cloning high-risk endangered species serves as an intervention. The end goal of cloning high-risk endangered species like the white rhino is to see the animals thrive and sustain themselves naturally and not be kept alive by human life-support. 

As is the case with Elizabeth Ann, cloning an endangered species could allow the animals to be reintroduced into a habitat to offset potential damage caused by their demise. With some critically endangered animals like the white rhino, cloning is simply the only method of saving species from complete extinction. 

So when it comes to the pros and cons of animal cloning, from the perspective of rescuing an entire species from extinction, it’s hard to make a case that animal cloning is a bad thing. 

Now, Elizabeth Ann’s DNA came from an animal that had been dead for over three decades, so her cloning might seem understandably creepy. However, though endangered, the black-footed ferret does indeed exist in limited populations in the wild. This brings us to the next question when examining the pros and cons of animal cloning. 

Could we resurrect a species that was already extinct, and if so, what could happen? 

Cloning Already Extinct Animals 

When it comes to the pros and cons of animal cloning, anyone who’s watched the movie franchise Jurassic Park is intimately familiar with the potential negative outcome of cloning extinct species. 

So what would happen if scientists cloned an animal that had long been extinct, like the saber-toothed tiger, woolly mammoth, or as is the case in Jurassic Park , a Velociraptor or Tyrannosaurus Rex? 

Fortunately for anyone who’s seen the habitual outcome in the movies (or unfortunately, if your thinking happens to align with the wealthy eccentric fictional character, John Hammond), resurrecting long-extinct dinosaurs is impossible. “The limit of DNA survival, which we’d need for de-extinction, is probably around one million years or less. Dinosaurs had been gone for a very long time by then,” said  Dr. Beth Shapiro, an expert in ancient DNA and biologist at the University of California. 

Even though the outcome always ends in tragedy, at least in the movies, one can’t help but feel a little let down by the news that we’ll never get a chance to see Earth’s ancient reptile rulers up close. 

Nevertheless, with dinosaurs off the table, there are still many species that have gone extinct we might be able to clone. There happens to be an entire scientific discipline called “ resurrection biology ” that examines doing just that. 

If you have not previously heard of resurrection biology, which sounds more like sorcery than science, you’re likely equally unfamiliar with the fact that scientists have already reanimated a species that had gone extinct. Albeit very briefly. 

In 2000, the Pyrenean ibex, a goat native to the Pyrenees , was declared extinct. Given that by 1913, ecologists already knew the species population had been reduced to less than 100, its loss has been called  a significant “EU conservation failure.” 

Yet, using skin cells from the last known ibex, which had died in late 1999, scientists were able to successfully make cloned embryos by inserting the ibex’s DNA into domestic goat eggs emptied of their original genetic material. 

The cloned embryos were then implanted into another subspecies of Spanish ibex or goat-ibex hybrids. Of 208 implanted embryos, seven goats became pregnant, with just one making it to term. On July 30, 2003, the  first-ever cloned extinct species  was born. 

Unfortunately, the Pyrenean ibex’s revival in the animal kingdom only lasted a few minutes. The newborn ibex had been born with an extra lobe in its left lung, causing the kid to succumb to respiratory distress syndrome and die six minutes after it was born. So far, researchers have not successfully cloned the Pyrenean ibex, and the mountain goat remains extinct. 

The difficulty in cloning a species is hardly limited to the Pyrenean ibex. With current technology, the act of shuffling DNA from one cell to another, causing developmental irregularities and abnormalities, is prevalent. 

Even when cells can be extracted and a cloned embryo successfully cultivated, scientists have to overcome another huge obstacle when working with an extinct species. There aren’t any appropriate surrogate mothers. 

Underscoring the difficulties in resurrecting an extinct species, consider with the Pyrenean ibex, researchers had the benefit of beginning their attempts almost immediately after the last goat died. Attempting to clone a species that has been gone for tens-to-hundreds-of-thousands of years is exceedingly more difficult. 

In fact, rather than using the process of somatic cell nuclear transfer – how Dolly the Sheep and Elizabeth Ann were created – to attempt the resurrection of an extinct species, scientists must engage in a process in which DNA is inserted, deleted, modified, or replaced in the genome of an organism. This technique is called genome editing or genome engineering. 

Due to  controversies surrounding the topic  and an often contentious public view , many are probably familiar with the term describing an organism’s successful genetic editing for increased food yield –  GMO (genetically modified organism) . 

To revive an animal long wiped out, resurrection biologists have to use cells from a closely related species and then modify those cells so that a living species produce offspring of an extinct species. A species that is at the forefront of de-extinction science right now is the  woolly mammoth . 

Disappearing roughly 3,700 years ago, scientists have well preserved soft tissue remains and DNA from woolly mammoths. Unfortunately, even the  most intact mammoth samples lack enough DNA to guide the production of an embryo. To overcome this, scientists have been examining using new molecular tools to edit the genomes of elephants to alter their DNA sequences to mammoth DNA. If successful, the result wouldn’t be a woolly mammoth clone, but rather a hybrid that would be mostly elephant, and a little bit mammoth. 

“If you mean 100-percent mammoth, with all mammoth genes and behaviors, that will never happen,” says Dr. Shapiro on the likelihood of ever fully cloning a woolly mammoth. 

If an extinct species can never really be restored, is there any reason for de-extinction outside of novelty? 

A June 2013 editorial by  Scientific American  criticized efforts to reanimate lost species on the basis the idea misses the mark when it comes to conservation. Editors argued that with “limited intellectual bandwidth and financial resources,” the attention-grabbing de-extinction topic diverts attention from the current biodiversity crisis. 

“A program to restore extinct species poses a risk of selling the public on a false promise that technology alone can solve our ongoing environmental woes—an implicit assurance that if a species goes away, we can snap our fingers and bring it back.” 

As far as pros and cons of animal cloning, the Scientific American editors said they stood behind efforts to prevent extinction, highlighting the black-footed ferret and white rhino as examples. 

Responding to the criticism raised by Scientific American, professor of genetics at Harvard Medical School and Director of the National Institutes of Health Center of Excellence in Genomic Science at Harvard, Dr. George Church, clapped back, suggesting the authors were the ones missing the point. 

For Dr. Church, it goes back to the grey wolves and Yellowstone National Park and the evidence of how impactful one “keystone” species can be, not just to one habitat but the entire world’s ecosystem. 

Thousands of years ago, the ice-covered tundras of Russia and Canada was home to the woolly mammoth. During that time, the area was home to a rich grass-and-ice-based ecosystems. Today, those tundras are melting, and according to Dr. Church, if this continues, it could release more greenhouse gas “than all the world’s forest would if they were burned to the ground.” 

A few genetic modifications to the modern elephant’s DNA could create a hybrid animal functionally similar to the mammoth. By reintroducing woolly mammoth hybrids to the tundras, the animals could single-handedly stave off an environmental crisis.

In an  essay published in Scientific American , Church outlines three significant ways mammoth hybrids would restore balance to the world’s coldest regions. 

• Eating dead grass, enabling the sun to reach spring grass, whose deep roots prevent erosion. 
• Increasing reflected light by felling trees, which absorb sunlight. 
• Punching through insulating snow so that freezing air penetrates the soil. 

Dr. Church provides a compelling case for why cloning for de-extinction is far from a novelty. As grey wolves demonstrated, the woolly mammoth’s return could have a significant positive impact on our planet’s ecology. However, objectively it’s essential to remember this is entirely uncharted territory for humanity, with considerable unknowns. 

Reintroducing a species that has been extinct for thousands of years could have the exact opposite effect as the grey wolf. An extinct species could easily be viewed as an invasive species by its former habitat. Instead of restoring balance, it could throw-off an ecosystem in ways we didn’t foresee. 

Given the ongoing and over a year-long struggle the world has endured with the COVID-19 pandemic, it’s also important to consider that reintroducing extinct animals could end up creating new opportunities for bacteria and viruses to develop. Even if a species was merely a hybrid, it’s hard to predict whether that might be enough to reinvigorate the conditions to foster ancient bacterial strains. Equally unknown, to what effect could archaic bacteria have on human health? 

Ultimately, there are theoretical arguments on both sides when it comes to the pros and cons of animal cloning of extinct animals. However, too many unknowns prevent us from truly knowing which side of the scale weighs the heaviest. 

Pros and Cons of Animal Cloning For Food 

Thus far, we’ve examined the pros and cons of animal cloning that can indirectly impact people’s daily lives. However, whether you realize it or not, it’s highly likely you’ve been experiencing the byproducts of animal cloning for years and didn’t even know it. 

With the breakthrough cloning of Dolly the Sheep, agricultural scientists realized cloning could duplicate prize breeding animals. Facing the potential to ensure greater yields and better meats, by the early 2000s, an entire industry surrounding the genetic modification of cows, pigs, and goats exploded on the scene. 

In truth, cloning is an expensive venture, so the overwhelming majority of livestock clones are used as breeding stock and not butchered for meat. Yet, it’s almost sure that aside from vegans, everyone has dined on beef that has come from the cloned offspring.

In 2008, the  U.S. Food and Drug Administration (FDA) declared  meat and milk from clones of cattle, swine, and goats to be “as safe to eat as food from conventionally bred animals.” Adding insult to injury for those expressing concerns, the FDA ruled that cloned food is not required to be labeled, preventing consumers’ ability to avoid meats coming from cloned animals. 

Criticizing the conclusions of the FDA’s 2008 “risk assessment,” opponents have argued cloning science is too new, not well understood, and too imprecise to adequately measure the risks. 

Pointing to their own study, the  Center for Food Safety  notes that even the FDA acknowledged in their risk assessment that “a vast quantity of animal clones are unhealthy and would not be suitable for the food supply.” 

Critics say that acknowledging the majority of cloned animals is not suitable for food supply but still approving the process for consumption; the FDA fails to address that defects in cloned animals can easily escape detection and enter human food supplies. A study performed by the National Academy of Sciences  (NAS) concluded that no method for detecting subtle health problems in clones exists. 

As the market for cloned livestock took off in the early 2000s, Sir Ian Wilmut, lead research scientist that cloned Dolly the Sheep,  expressed his reservations concerning science he helped develop being used for genetically enhanced foods. “Cattle cloners ought to be making systematic comparisons between clones and animals produced by embryo transfer, looking not just at their milk yield but also their health and lifespan,” said Wilmut. 

A 2013 study  concluded  that cloned cattle that reached adulthood and entered the food supply were essentially equivalent to conventional cattle concerning meat and milk quality. 

Consumer advocates also raise many concerns about the high doses of hormones and antibiotics used in the cloning process. Surprisingly little research has been done on the health effects of hormones used with cloned livestock, so the impact on human health isn’t entirely clear. 

Because the practice hasn’t been around long enough, the potential for adverse long-term effects from cloned food consumption is even less clear. 

Advocates of animal husbandry cloning  contend  the process allows for exact genetic copies of top breeding stock to be replicated, thereby producing healthier, superior livestock. 

China has Achieved Total Global Drone Supremacy China dominates the drone market, both from a commercial and militairy perspective.

“Cloning reproduces the healthiest animals, thus minimizing the use of antibiotics, growth hormones and other chemicals,”  reads a statement  provided by the Biotechnology Industry Organization. “Consumers can benefit from cloning because meat and milk will be more healthful, consistent, and safe.” 

Like resurrecting long-dead species, the pros and cons of animal cloning for food sources are difficult to measure. The majority of public opinion has  never polled favorably  regarding cloning and animal husbandry. However, that alone doesn’t necessitate the practice is inherently harmful. 

Ultimately, unlike de-extinction cloning, livestock’s genetic engineering is very much a significant part of the modern agricultural industry. Whether or not this is a good or bad thing is a consequence we’ll likely have to live with, no matter the outcome. 

We’ve examined the pros and cons of animal cloning and how it affects human beings and the environment. However, the most contentious slippery slope surrounding the entire topic of animal cloning is the ethical debate and the potential negative consequences on the very animal life being used. 

Ethical Pros and Cons of Animal Cloning 

Is it morally right to create a life that would not otherwise come about naturally? When it comes to the pros and cons of animal cloning, this isn’t a question that can be answered by science or ground truth. As is the case with all moral issues, the ethical terrain surrounding animal cloning is complex. 

Yet, it’s arguably the most crucial question that vexes the public and genetic scientists alike. 

For some, there exists a principled argument against humanity effectively playing God, choosing life and death over other living creatures. For others, the ethical concerns center on more nuanced yet tangible and disturbingly brazen aspects of animal cloning. 

Arguably, the most compelling moral argument is the genuine suffering often endured by the animals involved in genetic science. The pain and suffering animals experience during cloning procedures, obstetrical complications that occur with surrogate mothers, and cloned animals’ health are genuine issues. 

Success rates of cloning procedures in producing live offspring, called “efficiency” in cloning science, are pretty grim. Studies have shown the differing efficiency rates based on the somatic cell type used, ranging from 30% to 93%, of clone pregnancies resulting in miscarriages. A  separate study  found that less than 5% of cloned embryos transferred into recipient cows survive. 

When live-births occur,   research has shown mortality rates to be as high as 50%. Basically, a coin toss decides if a cloned animal ends up dying within 130 days due to chronic health issues. 

The overwhelming bulk of past research on animal cloning involves examining the efficiency rates of somatic cell transfer, which  currently shows  success rates of 5%-20% for cows and 1%-5% for other species. Little research, however, exits on the health of cloned animals into adulthood. 

A  2016 study on cloned sheep, including four from the same cell lines as Dolly, found no evidence of late-onset, non-communicable diseases. “We could find no evidence, therefore, of a detrimental long-term effect of cloning by SCNT on the health of aged offspring among our cohort,” said the study’s authors. 

In light of the researcher’s findings, the proverbial elephant in the room is that when Dolly passed away at 6.5 years old from lung disease and severe arthritis, she had only lived around half of the typical 12-year life expectancy of a Finn Dorset sheep. 

Some  speculated  Dolly could have been born with the genetic age of the cell donor used to create her, who was six at the time of cell transfer. Researchers, however,  said they found no evidence  of Dolly being born at an advanced age, and her heirs have all gone on to live long, healthy lives. 

Adding an entirely new wrinkle in the ethical pros and cons of animal cloning, in 2019, scientists at the Institute of Neuroscience (ION) in Shanghai announced they had successfully  cloned five identical macaque monkeys . As if cloning human beings’ primate cousins weren’t already concerning, Chinese scientists purposefully cloned the macaque monkeys to suffer health issues. 

To unravel the mechanisms behind complex human disorders, such as Alzheimer’s, scientists at ION used gene-editing to disable a gene crucial to the monkey’s sleep-wake cycle. “Primates are the best animal model for studying higher cognitive functions and brain disorders in humans,” said neuroscientist Mu-ming Poo, ION’s director, and co-founder. 

With their five identical cloned monkeys, researchers at ION intend to study the effects of circadian rhythm disorders in hopes of better understanding and ultimately finding cures for human beings who suffer from sleep disorders. 

Initial results of the study on circadian rhythms using the cloned monkeys were published in the journal of National Science Review – of which Mu-ming Poo is Executive Editor-in-Chief. Poo said researchers did this because “the journal needs publicity” but denied being involved in the review process. 

An animal ethics statement published with the study reads, “The use and care of cynomolgus monkeys ( M .  fascicularis ) complied with the guidelines of the Animal Advisory Committee at the Shanghai Institutes for Biological Science, Chinese Academy of Sciences.” 

In 2019, Poo  said  Chinese researchers were already planning to use cloned primates to model other brain diseases, such as Alzheimer’s disease, Parkinson’s disease, a severe genetic intellectual disability called Angelman syndrome, and several genetic eye disorders. 

A statement issued by the People for the Ethical Treatment of Animals (PETA), an animal rights group based in Norfolk, Virginia, called ION’s research “a monstrous practice that causes [the monkeys] to suffer.” 

Whether it be for conservation, de-extinction, livestock use, or medical research, proponents solve animal cloning’s moral question by the adage, “the ends justify the means.” Specifically, the benefit to humanity through animal cloning outweighs any suffering and health-risk, or even purposeful manipulation to cause disease, caused through the cloning process. 

It’s vital to be abundantly clear. Just like the editors of Scientific American advocated using animal cloning for the conservation of endangered species, but shunned de-extinction, there is no single ethical solution amongst the varied domains of cloning science. 

The Debrief set out to examine the pros and cons of animal cloning. However, once one digs into the topic, one finds there is no simple answer. There is no universal conclusion as to whether cloning is fundamentally a positive or negative thing. 

There are compelling arguments on both sides, with some avenues, such as cloning for conservation, seemingly more acceptable. In these instances, realizing the alternative means the loss of an entire species can mitigate the pain, suffering, or low “efficiency” involved in the process. 

Meanwhile, other areas, such as cloning for medical research, even when that research may benefit humankind, leave one with a sense of disgust and simply feel morally wrong. 

Should science be involved in the cloning animals? Vote and let us know your thoughts in the comments. Make sure to check out The Debrief’s feature coming out today where we examine -The Pros and Cons of Animal Cloning. — The Debrief (@Debriefmedia) February 25, 2021

Some may argue that science is the quest for objective knowledge and should be divorced from ethical considerations. However, this view discounts the fact that, as the pursuers of knowledge, human beings are creatures capable of taking a holistic view and considering the broader consequences of their actions. 

Going back to Yellowstone National Park’s case, the overpopulation of deer and elk caused the depletion of natural resources, negatively impacting the entire ecosystem. Yet, these acts were not immoral, and the animals were incapable of measuring the consequences of their overconsumption. 

Conversely, human beings cannot claim such ignorance. We are more than capable of discerning the impact of our actions on ourselves and the world around us. We must use that holistic lens when examining animal cloning to measure risk vs. reward, both in the near and short term, and the principled impact on society. 

Ultimately, Dr. Shapiro best sums up the dilemma of animal cloning in her book, How to Clone a Mammoth: The Science of De-Extinction . Describing her work examining how to resurrect extinct species, Dr. Shapiro calls it “Exhilarating because of the unprecedented opportunities to understand life and boost conservation efforts, but terrifying in part for its ethical quandaries.”

Join us on Twitter or Facebook to weigh in and share your thoughts on the pros and cons of animal cloning. You can also follow all the latest  news and exciting feature content from The Debrief on Flipboard , Instagram , and don’t forget to subscribe to The Debrief YouTube Channel and check out The Official Debrief Podcast . 

Should science be involved in the cloning animals? Let us know your thoughts in the comments and make sure to check out… Posted by The Debrief on  Thursday, February 25, 2021

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International Journal of Science, Technology and Society

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Scientific and Ethical Implications of Human and Animal Cloning

Sidra Shafique

Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada

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Cloning is an old paradigm with new ethical issues that society is confronting today and will do so tomorrow. In this publication, cloning has been reviewed from the perspective of its broad implications on research, agriculture, pets, sports animals and humans. Reflection of legal status shows a picture of cloning applications that is not only inevitable but expected to change human species forever. Weighing advantages vs disadvantages of either the reproductive cloning or therapeutic one sums up into unnatural acts, changing the diversity of society and risks of exploitation. Modern biotechnology can only clone the genomes, not the individuals. Cultural inheritance comes from the development and adaptation of individuality generation after generation. The biological inheritance may be copied but the cultural inheritance cannot be duplicated. Human cloning infringes upon the principles of individual freedom, identity, and autonomy. Here, the current impacts of cloning are elaborated in comparison to the past and predicting what could happen tomorrow. In any scenario, public discussion and involvement of society must be preceded by making or amending laws and regulations. Risk assessment, enforcing justice and altered explanation of ‘words’ and ‘definitions might be the next stance for bioethicists and lawyers shortly. However, scientists and the regulatory authorities are of the view that the way IVF and animal cloning have been gradually accepted, the fourteen days blastocyst cultivation has been justified, one day the human cloning will also get the approval of a common man. As science will advance, the ethicist and theologists would come up with a favorable argument too, maybe three decades from now. In the present publication, the issue of cloning in general with a focus on human cloning, in particular, is discussed understandably by everyone interested in cloning and its impacts on society.

Human Cloning, Animal Cloning, Ethical Issues, Reproductive Cloning, Legislation, Cultural Inheritance

Sidra Shafique. (2020). Scientific and Ethical Implications of Human and Animal Cloning. International Journal of Science, Technology and Society , 8 (1), 9-17. https://doi.org/10.11648/j.ijsts.20200801.12

Sidra Shafique. Scientific and Ethical Implications of Human and Animal Cloning. Int. J. Sci. Technol. Soc. 2020 , 8 (1), 9-17. doi: 10.11648/j.ijsts.20200801.12

Sidra Shafique. Scientific and Ethical Implications of Human and Animal Cloning. Int J Sci Technol Soc . 2020;8(1):9-17. doi: 10.11648/j.ijsts.20200801.12

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Cloning Fact Sheet

The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. The copied material, which has the same genetic makeup as the original, is referred to as a clone. Researchers have cloned a wide range of biological materials, including genes, cells, tissues and even entire organisms, such as a sheep.

Do clones ever occur naturally?

Yes. In nature, some plants and single-celled organisms, such as bacteria , produce genetically identical offspring through a process called asexual reproduction. In asexual reproduction, a new individual is generated from a copy of a single cell from the parent organism.

Natural clones, also known as identical twins, occur in humans and other mammals. These twins are produced when a fertilized egg splits, creating two or more embryos that carry almost identical DNA . Identical twins have nearly the same genetic makeup as each other, but they are genetically different from either parent.

What are the types of artificial cloning?

There are three different types of artificial cloning: gene cloning, reproductive cloning and therapeutic cloning.

Gene cloning produces copies of genes or segments of DNA. Reproductive cloning produces copies of whole animals. Therapeutic cloning produces embryonic stem cells for experiments aimed at creating tissues to replace injured or diseased tissues.

Gene cloning, also known as DNA cloning, is a very different process from reproductive and therapeutic cloning. Reproductive and therapeutic cloning share many of the same techniques, but are done for different purposes.

What sort of cloning research is going on at NHGRI?

Gene cloning is the most common type of cloning done by researchers at NHGRI. NHGRI researchers have not cloned any mammals and NHGRI does not clone humans.

How are genes cloned?

Researchers routinely use cloning techniques to make copies of genes that they wish to study. The procedure consists of inserting a gene from one organism, often referred to as "foreign DNA," into the genetic material of a carrier called a vector. Examples of vectors include bacteria, yeast cells, viruses or plasmids, which are small DNA circles carried by bacteria. After the gene is inserted, the vector is placed in laboratory conditions that prompt it to multiply, resulting in the gene being copied many times over.

How are animals cloned?

In reproductive cloning, researchers remove a mature somatic cell , such as a skin cell, from an animal that they wish to copy. They then transfer the DNA of the donor animal's somatic cell into an egg cell, or oocyte, that has had its own DNA-containing nucleus removed.

Researchers can add the DNA from the somatic cell to the empty egg in two different ways. In the first method, they remove the DNA-containing nucleus of the somatic cell with a needle and inject it into the empty egg. In the second approach, they use an electrical current to fuse the entire somatic cell with the empty egg.

In both processes, the egg is allowed to develop into an early-stage embryo in the test-tube and then is implanted into the womb of an adult female animal.

Ultimately, the adult female gives birth to an animal that has the same genetic make up as the animal that donated the somatic cell. This young animal is referred to as a clone. Reproductive cloning may require the use of a surrogate mother to allow development of the cloned embryo, as was the case for the most famous cloned organism, Dolly the sheep.

What animals have been cloned?

Over the last 50 years, scientists have conducted cloning experiments in a wide range of animals using a variety of techniques. In 1979, researchers produced the first genetically identical mice by splitting mouse embryos in the test tube and then implanting the resulting embryos into the wombs of adult female mice. Shortly after that, researchers produced the first genetically identical cows, sheep and chickens by transferring the nucleus of a cell taken from an early embryo into an egg that had been emptied of its nucleus.

It was not until 1996, however, that researchers succeeded in cloning the first mammal from a mature (somatic) cell taken from an adult animal. After 276 attempts, Scottish researchers finally produced Dolly, the lamb from the udder cell of a 6-year-old sheep. Two years later, researchers in Japan cloned eight calves from a single cow, but only four survived.

Besides cattle and sheep, other mammals that have been cloned from somatic cells include: cat, deer, dog, horse, mule, ox, rabbit and rat. In addition, a rhesus monkey has been cloned by embryo splitting.

Have humans been cloned?

Despite several highly publicized claims, human cloning still appears to be fiction. There currently is no solid scientific evidence that anyone has cloned human embryos.

In 1998, scientists in South Korea claimed to have successfully cloned a human embryo, but said the experiment was interrupted very early when the clone was just a group of four cells. In 2002, Clonaid, part of a religious group that believes humans were created by extraterrestrials, held a news conference to announce the birth of what it claimed to be the first cloned human, a girl named Eve. However, despite repeated requests by the research community and the news media, Clonaid never provided any evidence to confirm the existence of this clone or the other 12 human clones it purportedly created.

In 2004, a group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science in which it claimed to have created a cloned human embryo in a test tube. However, an independent scientific committee later found no proof to support the claim and, in January 2006, Science announced that Hwang's paper had been retracted.

From a technical perspective, cloning humans and other primates is more difficult than in other mammals. One reason is that two proteins essential to cell division, known as spindle proteins, are located very close to the chromosomes in primate eggs. Consequently, removal of the egg's nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division. In other mammals, such as cats, rabbits and mice, the two spindle proteins are spread throughout the egg. So, removal of the egg's nucleus does not result in loss of spindle proteins. In addition, some dyes and the ultraviolet light used to remove the egg's nucleus can damage the primate cell and prevent it from growing.

Do cloned animals always look identical?

No. Clones do not always look identical. Although clones share the same genetic material, the environment also plays a big role in how an organism turns out.

For example, the first cat to be cloned, named Cc, is a female calico cat that looks very different from her mother. The explanation for the difference is that the color and pattern of the coats of cats cannot be attributed exclusively to genes. A biological phenomenon involving inactivation of the X chromosome (See sex chromosome ) in every cell of the female cat (which has two X chromosomes) determines which coat color genes are switched off and which are switched on. The distribution of X inactivation, which seems to occur randomly, determines the appearance of the cat's coat.

What are the potential applications of cloned animals?

Reproductive cloning may enable researchers to make copies of animals with the potential benefits for the fields of medicine and agriculture.

For instance, the same Scottish researchers who cloned Dolly have cloned other sheep that have been genetically modified to produce milk that contains a human protein essential for blood clotting. The hope is that someday this protein can be purified from the milk and given to humans whose blood does not clot properly. Another possible use of cloned animals is for testing new drugs and treatment strategies. The great advantage of using cloned animals for drug testing is that they are all genetically identical, which means their responses to the drugs should be uniform rather than variable as seen in animals with different genetic make-ups.

After consulting with many independent scientists and experts in cloning, the U.S. Food and Drug Administration (FDA) decided in January 2008 that meat and milk from cloned animals, such as cattle, pigs and goats, are as safe as those from non-cloned animals. The FDA action means that researchers are now free to using cloning methods to make copies of animals with desirable agricultural traits, such as high milk production or lean meat. However, because cloning is still very expensive, it will likely take many years until food products from cloned animals actually appear in supermarkets.

Another application is to create clones to build populations of endangered, or possibly even extinct, species of animals. In 2001, researchers produced the first clone of an endangered species: a type of Asian ox known as a guar. Sadly, the baby guar, which had developed inside a surrogate cow mother, died just a few days after its birth. In 2003, another endangered type of ox, called the Banteg, was successfully cloned. Soon after, three African wildcats were cloned using frozen embryos as a source of DNA. Although some experts think cloning can save many species that would otherwise disappear, others argue that cloning produces a population of genetically identical individuals that lack the genetic variability necessary for species survival.

Some people also have expressed interest in having their deceased pets cloned in the hope of getting a similar animal to replace the dead one. But as shown by Cc the cloned cat, a clone may not turn out exactly like the original pet whose DNA was used to make the clone.

What are the potential drawbacks of cloning animals?

Reproductive cloning is a very inefficient technique and most cloned animal embryos cannot develop into healthy individuals. For instance, Dolly was the only clone to be born live out of a total of 277 cloned embryos. This very low efficiency, combined with safety concerns, presents a serious obstacle to the application of reproductive cloning.

Researchers have observed some adverse health effects in sheep and other mammals that have been cloned. These include an increase in birth size and a variety of defects in vital organs, such as the liver, brain and heart. Other consequences include premature aging and problems with the immune system. Another potential problem centers on the relative age of the cloned cell's chromosomes. As cells go through their normal rounds of division, the tips of the chromosomes, called telomeres, shrink. Over time, the telomeres become so short that the cell can no longer divide and, consequently, the cell dies. This is part of the natural aging process that seems to happen in all cell types. As a consequence, clones created from a cell taken from an adult might have chromosomes that are already shorter than normal, which may condemn the clones' cells to a shorter life span. Indeed, Dolly, who was cloned from the cell of a 6-year-old sheep, had chromosomes that were shorter than those of other sheep her age. Dolly died when she was six years old, about half the average sheep's 12-year lifespan.

What is therapeutic cloning?

Therapeutic cloning involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease. To date, there is no evidence that human embryos have been produced for therapeutic cloning.

The richest source of embryonic stem cells is tissue formed during the first five days after the egg has started to divide. At this stage of development, called the blastocyst, the embryo consists of a cluster of about 100 cells that can become any cell type. Stem cells are harvested from cloned embryos at this stage of development, resulting in destruction of the embryo while it is still in the test tube.

What are the potential applications of therapeutic cloning?

Researchers hope to use embryonic stem cells, which have the unique ability to generate virtually all types of cells in an organism, to grow healthy tissues in the laboratory that can be used replace injured or diseased tissues. In addition, it may be possible to learn more about the molecular causes of disease by studying embryonic stem cell lines from cloned embryos derived from the cells of animals or humans with different diseases. Finally, differentiated tissues derived from ES cells are excellent tools to test new therapeutic drugs.

What are the potential drawbacks of therapeutic cloning?

Many researchers think it is worthwhile to explore the use of embryonic stem cells as a path for treating human diseases. However, some experts are concerned about the striking similarities between stem cells and cancer cells. Both cell types have the ability to proliferate indefinitely and some studies show that after 60 cycles of cell division, stem cells can accumulate mutations that could lead to cancer. Therefore, the relationship between stem cells and cancer cells needs to be more clearly understood if stem cells are to be used to treat human disease.

What are some of the ethical issues related to cloning?

Gene cloning is a carefully regulated technique that is largely accepted today and used routinely in many labs worldwide. However, both reproductive and therapeutic cloning raise important ethical issues, especially as related to the potential use of these techniques in humans.

Reproductive cloning would present the potential of creating a human that is genetically identical to another person who has previously existed or who still exists. This may conflict with long-standing religious and societal values about human dignity, possibly infringing upon principles of individual freedom, identity and autonomy. However, some argue that reproductive cloning could help sterile couples fulfill their dream of parenthood. Others see human cloning as a way to avoid passing on a deleterious gene that runs in the family without having to undergo embryo screening or embryo selection.

Therapeutic cloning, while offering the potential for treating humans suffering from disease or injury, would require the destruction of human embryos in the test tube. Consequently, opponents argue that using this technique to collect embryonic stem cells is wrong, regardless of whether such cells are used to benefit sick or injured people.

Last updated: August 15, 2020

117 Cloning Essay Topic Ideas & Examples

🏆 best cloning topic ideas & essay examples, 💡 most interesting cloning topics to write about, 📌 simple & easy cloning essay titles, 👍 good essay topics on cloning, ❓ cloning questions.

• Animal Cloning Benefits and Controversies This inefficiency of animal cloning depicts the consequences the animals have to experience, especially the donor and surrogate animals where surgery has to be performed to extract the cells of interest and implant the embryos.
• Ethics of Cloning It is important to understand that cloning is not associated with the production of a clone that has the same size and age as its donor, but rather, it is a form of twinning referred […] We will write a custom essay specifically for you by our professional experts 808 writers online Learn More
• The Cloning Controversy Considering the fact that most of the controversy about cloning arises from misinformation or ignorance about the matter, this study shall set out to conclusively research on cloning and its merits so as to attest […]
• DNA Cloning and Sequencing: The Experiment The plasmid vector pTTQ18 and the GFP PCR product will be digested with restriction enzymes and the desired DNA fragments obtained thereof will be purified by Polyacrylamide gel electrophoresis and ligated with DNA ligase resulting […]
• Human Cloning Considerations Analysis The multitude of the biologically born have no way of knowing their fathers and mothers and have all the rights in human society, and no one can even afford to think about violating them.
• Aspects of Cloning for Medical Purposes The second reason for the industry’s support is the cloning of vital organs for use in medicine, as it is known that there is a shortage of donor organs in the world.
• Human Cloning and Kantian Ethics The current paper will define the issue of human cloning through the prism of Kantian ethics and support the idea of reproductive cloning being a contravention of human dignity and fundamental biological principles.
• The Human Cloning Issue and Ethics Additionally, as expressed by Ayala, “the biological endowment of mankind is rapidly deteriorating,” and cloning allows us to resolve such issues. As seen in the example of Frankenstein, “breatheless horror and disgust” are followed by […]
• Cloning, 3D Printing, and Artificial Parts: Replacement Strategies The possibility to turn such cells into any other is the main advantage of the method. This is 3D printing, apparently; as mentioned, it continues to grow more popular in medicine, which calls for studying […]
• Cloning: Genetically Identical Copy The clone develops in the womb and eventually, the adult female gives birth, with the new clone having an identical genetic makeup to the organism from which the somatic cell originated.
• Human Cloning and the Challenge of Regulation Cloning is, therefore, a highly beneficial process from a scientific standpoint, and it has the potential to usher in a new era of technological progress.
• Should Cloning Be 100% Legal or Illegal? After all, an embryo is recognized as a living organism, and for cloning experiments, embryo cells would have to be killed in the research.
• Genetic Modification and Cloning Even though it is hard to predict all the outcomes of genetic modification and cloning, I would suggest using CRISPR Cas9 in treating retinal diseases such as the one described in the case study.
• Religious Perspective on Human Cloning The cloning of embryos exposes little humans to the danger of death. The article evaluates the position of religions in the world of technological reproduction.
• Cloning Humans as a Controversial Question In this case, the offender is likely to cheat on the police to make the innocent be imprisoned and then continue to break the law.
• Genetics, Reproductive and Cloning Technology in “Frankenstein” If Mary Shelley was for the idea of cloning technology, I think her novel would have ended up with Frankenstein creating a female companion for the monster to compliment the theme of love in the […]
• The Case of Human Cloning at Kyunghee University The objective of the KUMC in the research was to conduct in vitro fertilization of the ova but the researchers went ahead and performed human cloning using some of the ova that they had obtained […]
• Counterarguments to Human Cloning One of the most controversial is the attempt to reproduce an exact replica of a human being through the process of cloning.
• Ethical Debate on Human Cloning Cloning refers to the scientific multiplication and production of new cells to reproduce individuals that resemble their natural counterparts. These proponents insist that cloning will lead to the production of individuals that are resistant to […]
• Controversies in Therapeutic Cloning The embryonic cells have a potential to transform into any type of cell in the body and because of this, opponents of therapeutic cloning assert that the procedure equates murder.
• The Concept of DNA Cloning In the approach based on cells both the replicating molecule or the biological vehicle known as the vector and the foreign DNA fragment are cut using the same restriction enzyme to produce compatible cohesive or […]
• Can Cloning Technology Be Useful for Endangered Species? This is because animal cloning is popularly understood as the creation of a copy of another animal, much the same way as the capability to create twins but in the laboratory.
• Animal and Reproductive Cloning: Current Events It is the nucleus that contains the DNA of the donor. Its DNA structure is similar to the donor.”The blastocyst is then transferred to the uterus of a surrogate mother”.
• Cloning of Plants at the Botanic Garden Cloning is now considered to be an efficient means to grow plants in being the result of vegetative propagation while seeds are the result of the natural reproductive phenomenon of plants.
• Cloning and the Principles That Should Regulate It Since the research of the possibilities of cloning, as well as the opportunities that it opens for humankind, is still in process, it is worth stressing that the existing ethical principles have not been shaped […]
• Medical Ethics. Reproductive and Therapeutic Cloning I suppose that cloning is one of the breakthroughs that need the system of counterbalance providing a holistic approach to the problem.
• Definition, Benefits and Legislations on Human Cloning There are a number of ways in which the human cloning is beneficial to mankind the examples include: Better Understanding of Genetic Diseases.
• Cloning: Ethical Questions The discovery of DNA and its role in predetermining the physical and mental subtleties of one’s existence, allowed us to realize that it is now only a matter of time before we are going to […]
• Animal Cloning and Engineering Another issue of especial importance to people is the preservation of endangered species of animals and breeding perfect samples of a kind since the achievement of the desired objective in purely biological ways is more […]
• Cloning of Organisms and Its Approaches Artificial embryo twining is the traditional way of cloning and can be said to be the lowest technology in the art of cloning.
• Subsequent Cloning of PARK2 Gene The following description is a series of important events that led to the identification and subsequent cloning of the PARK2 gene responsible for Parkinson’s disease.
• Understanding the Human Cloning Concept All the religions of the world admit that the human beings were created by the God, and it is not in the human power to duplicate God’s creatures.
• Human Cloning Should Be Selectively Allowed Those who oppose the cloning of humans are concerned over the issue of the health of women, considering the large number of eggs that would be required for the process of human cloning and affirm […]
• Human Cloning Technology and Its Justification Since human cloning is still in the experimental stage and the criticism for and against the subject is replete with valid reasons rational thinkers will be put to the dilemma in agreeing with either of […]
• The Moral Case Against Cloning-for-Biomedical-Research In my view then it is a vain hope that researchers will be able to determine when a human person comes into existence simply by inspecting the biological and genetic evidence about the development of […]
• Therapeutic and Reproductive Cloning, Ethical Issues However, a common problem is that though the person may have consented to the use of his biological samples for genetic research, he may not be aware of the future developments of genetic research to […]
• No to Cloning for Medical Research Those who do not subscribe to cloning for biomedical research believe that the embryo is in fact “one of us”; a human life in process an equal member of the species “Homo Sapiens” in the […]
• Cloning Impact of Science & Technology on Society Technically speaking, cloning is a means of isolating particular parts of the genome in small fragments of DNA and making copies of and studying the sequence in another organism. And they should be open to […]
• Cloning, Expression, and Crystallisation of Pectate Lyase The emergence of molecular cloning has enhanced the application of pectate lyases in industrial processes of manufacturing natural fibres and fruit juices.
• Human Cloning as an Ethical Issue Cloning has retained the position of one of the most fascinating subjects, drawing the interest of researchers, sci-fi authors, and philosophers alike.
• Debate on Human Reproductive Cloning According to Baird, human cloning should be prohibited for the simple reason that the onus of justification will be placed on the shoulders of those performing the cloning rather than those who want the cloning […]
• Molecular Cloning of GFP Gene Molecular cloning is a set of methods in molecular biology that is used to obtain multiple copies of the target DNA fragment. Bacterial transformation is a process of recombinant DNA insertion into a host bacterial […]
• Molecular, Cell and Organism Cloning Techniques Cloning is the process of creating a physical entity that is a precise copy of another organism or cell. In biology, cloning is understood as a duplication of biological material DNA, a cell, or a […]
• Cloning in Terms of Society and Theology The aim of this paper is to establish the implications of cloning on society and understand the theologians are saying about cloning.
• Ethical Issues on Human Therapeutic and Reproductive Cloning The two types of cloning differ in the procedure involved and the objective of the process. In the case of reproductive cloning, the egg is already fertilized and its failure to develop into a complete […]
• Human and Animal Production Cloning Concepts This research paper thus seeks to examine the concept of human and animal reproductive cloning with an aim of investigating the tenets of this concept and the perspective of society on the issue from ethical, […]
• The Human Cloning Debates Nonetheless, the scientists opposed reproductive cloning claiming that the practice undermines the uniqueness of humankind and that it is unethical to put the lives of clones in a condition of being susceptible to harm or […]
• The State of Cloning in 2062 One of the concerns of those who are against cloning is that it is inhuman to collect, store and freeze the surplus embryos in order to use them later.
• The New Advancements in Cloning and the Ethical Debate Surrounding It Cellular cloning involves use of somatic cells to produce a cell line identical to the original cell, and this can be used to produce therapies like those of molecular cloning.
• Whether or Not Human Cloning Should Be Allowed One of the benefits of cloning is the fact that it is able to provide children to people with fertility problems. It is no wonder that the process of cloning cells to form embryos is […]
• The Concept of Human Cloning Human cloning on the other hand refers to the process of creation of genetically copy of a human. The Adult DNA cloning is the process that entails removing the DNA from the embryo and replacing […]
• The Issue of Cloning as Described in Aldous Huxley’s Brave New World
• What Are the Ethical Issues of Human Cloning
• Why is Human Cloning Considered Unethical
• The Practical and Ethical Issues Surrounding the Cloning of Human Cells
• What Would the World be Like with Human Cloning
• Why Animal Cloning And Its Funding Should Be Stopped
• The Issue of Surrogate Motherhood in the Cloning Debate
• Why Human Cloning Should Be Allowed
• The Portrayal of World Full of Faceless Human Cloning in Huxley’s A Brave New World
• The Positive Impact of Human Cloning in the Modern World
• The Perils of Cloning and Its Commercialization for Human Reproduction
• Three Reasons Why Cloning Should Not Be Allowed
• The Controversy Surrounding Cloning in the United States
• The Positive and Negative Effects of Using Cloning to Treat Genetic Disease
• The Mass Production of Humans: Why Cloning is Unethical
• The Issues Surrounding The Possibility Of Modern Day Artificial Cloning
• The Question of Whether There Is a Good Side to Human Cloning
• The Analysis of Genetic Engineered Cloning in Modern Society and Alterations to the DNA
• The National Bioethics Advisory Commission’s Perspective on Human Cloning
• Understanding Cloning, Its Effects on Humans, and Its Advantages
• Understanding the Issues of Cloning
• The Need for Regulation of Biotechnology, Bioengineering, and Cloning
• Upgrading Cybercafé and Installing Cloning Software
• The Positive, Negative and Ethical Aspects of Human Cloning
• The Description of Cloning and the Scientific Advancement Toward Human Cloning
• The Potential Benefits of Cloning and Genetic Engineering to the Future of Society
• The Electric Potential of the Female Body Liquids and the Effectiveness of Cloning
• The Sensitivity of the Subject of Cloning
• The Significance of Cloning Mammals on Human Cloning
• The New Breakthrough in Cloning Is a Great Advance in Biotechnology
• The Several Compelling Reasons Why Cloning Should Not Be Legalized
• The Deficiencies of Artificial Cloning for Realistic Medical and Scientific Purposes
• The Important Points in the Controversial Ethical Issue of Human Cloning
• Therapeutic Cloning and Stem Cell Therapy in South Korea
• The United States Law Banning Genetic Cloning Of Humans
• The Theme of Cloning in Aldous Huxley’s Brave New World
• Therapeutic Cloning to Obtain Embryonic Stem Cells Is Immoral
• The Science And The Laws Impacting Human Cloning
• The Impact of Legalizing Cloning in our Society
• The History, Characteristics and FDA Regulation of Animal Cloning
• The Moral and Ethical Implications of Human Cloning
• Can Cloning and Christianity Coexist?
• Does Artificial Human Cloning Challenge Ethical Boundaries?
• What Are the Different Religious Approaches to Human Cloning?
• Should All Human Cloning Be Banned?
• Why Does Cloning Have Such a High Failure Rate?
• Has Cloning Been Accomplished in Humans?
• Does Cloning Have the Potential to Imperil the World?
• Why Should Human Cloning Be Prohibited?
• How Could Cloning Save a Species From Going Extinct?
• Does Human Cloning Produce an Embryo?
• Why Is Human Cloning Morally Wrong?
• How Has the Media Trained People on the Ethics of Cloning?
• What Type of Reproduction Is Cloning Humans?
• How Can Human Cloning Benefit Society?
• What Is a Positive Effect of Human Cloning?
• Should Human Reproductive Cloning Be Legal?
• What Problem Is Cloning Trying to Solve?
• Does Religion Really Allow Cloning?
• Why Is Cloning Bad for the Environment?
• How Does Human Cloning Violate Human Rights?
• What Are the Controversies of Cloning?
• How Would Human Cloning Affect Human Evolution?
• Why Cloning Is Bad for Genetic Diversity?
• Can Cloning Lead to Mutations?
• What Is the Future of Human Cloning?
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IvyPanda . 2024. "117 Cloning Essay Topic Ideas & Examples." March 2, 2024. https://ivypanda.com/essays/topic/cloning-essay-topics/.

1. IvyPanda . "117 Cloning Essay Topic Ideas & Examples." March 2, 2024. https://ivypanda.com/essays/topic/cloning-essay-topics/.

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IvyPanda . "117 Cloning Essay Topic Ideas & Examples." March 2, 2024. https://ivypanda.com/essays/topic/cloning-essay-topics/.

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Pros & Cons of Cloning Plants & Animals

Advantages & Disadvantages of Cloning

People are far more relaxed about plant cloning than animal cloning, which is quite understandable; but in the cloning debate, pros and cons are present for both. Because identical twins are naturally occurring clones, some people believe cloning is a technological version of a natural process, an argument used to justify the ethics of human cloning which is a controversial issue to say the least.

Pros And Cons Of Cloning Plants

Plant cloning is used to create hybrid strains of grains, fruit and vegetables, disease-resistant and high-yielding varieties that are reproduced exactly over and over. When it comes to food cloning pros and cons, the advantages outweigh the cons from a commercial faming viewpoint. However, this lack of diversity does not occur in nature. As varieties offer different disease-resistance levels, diversity protects crops from susceptibility to one disease which could wipe out a species worldwide.

Pros And Cons On Cloning Animals

Cloning Dolly, the first cloned sheep from an undifferentiated cell by nuclear transfer, was a massive achievement for science. However, the cloning process is far too costly to be commercially viable for farmers and breeders. One of the benefits of cloning animals is the exciting prospect of re-introducing a recently extinct species such as the Tasmanian Tiger, and its potential use for protecting other species nearing extinction. One disadvantage of animal cloning of an endangered species would also be the population's susceptibility of being wiped out by the same disease due to the identical genetic structure.

Pros And Cons Of Cloning Stem Cells

Stem-cell cloning has many pros due to its usefulness in regenerative medicine and cancer treatments and its hope for future potential, including organ cloning. Stem cells are harvested from the umbilical cord of newborns; parents can store their baby’s stem cells or donate them for research. As stem-cell cloning does not generally involve fertilized human embryos it is more widely accepted by the public, but it still raises social and ethical issues because stem cells can be extracted from human fetuses and fertilized embryos.

Pros And Cons Of Cloning Humans

The cloning of human parts certainly offers great hope for people on the organ donation list, as it would greatly prolong many lives and also remove the organ-rejection tendency due to mismatched DNA. Cloning whole humans, for instance super-kids, raises more concerns as it creates an unfair advantage to normal kids and could be seen as messing with the natural law of equality. Diversity is the key to evolution, an issue which human cloning contradicts. Another major con of human cloning is the strong ethical, religious and social issues going down this path would create.

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