Aim: How do scientists clone mammals?

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Why clone?

Cloning animals is a reliable way of maintaining high quality livestock to supply our nutritional needs. Identifying and reproducing superior livestock genetics ensures that herds are maintained at the highest quality possible.

Animal cloning offers great benefits to consumers, farmers, and endangered species:

Cloning allows farmers and ranchers to accelerate the reproduction of their most productive livestock in order to better produce safe and healthy food.
Cloning reproduces the healthiest animals, thus minimizing the use of antibiotics, growth hormones and other chemicals.
Cloning can be used to protect endangered species. For example, in China, panda cells are being kept on reserve should this species' numbers be threatened by extinction.

Process of Cloning

The most common cloning method, known as "somatic cell nuclear transfer" or simply "nuclear transfer," requires two kinds of cell. One is a somatic cell, which is collected from the animal that is to be cloned (known as the "genetic donor"). A somatic cell is any cell other than a sperm cell or egg cell, and contains the complete DNA, or genetic blueprint, of the animal it came from. For cloning purposes, somatic cells are typically obtained by a routine skin biopsy performed by a veterinarian.

The other kind of cell required for cloning is an egg cell, which is collected from a female of the same species (known as the "egg donor"). In the lab, a scientist extracts and discards the nucleus of the egg cell, which is the part of the cell that contains the egg donor's genes. The scientist then inserts the somatic cell from the genetic donor into the egg and "fuses" the two with electricity. The resulting fused egg contains the genetic donor's DNA.

The scientist stimulates the fused egg, which "activates" the egg and causes it to divide just as an egg would if it had been fertilized by a sperm cell in conventional reproduction. The activated egg is then placed in a culture medium. As cellular division continues over the course of several days, a blastocyst (early-stage embryo) forms. After about a week, an embryo transfer specialist transfers the blastocyst to a recipient female (sometimes referred to as "surrogate mother") where it continues to develop. After a full-term pregnancy, the recipient gives birth to an animal that is essentially the identical twin of the genetic donor.

https://www.youtube.com/watch?v=Krh7V3Z4Vr4

1. An organism that reproduces asexually will have offspring that have *

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1) the same genetic information as both of its parents.

2) the same genes as its parent.

3) different genetic information from either of its parents.

4) different genes form its parent.

2. In 1970, a deadly disease spread through corn crops in the United States. Scientists discovered that 80 percent of the corn contained the gene that made the plants more likely to be infected with the disease. This problem might have been avoided if the cornfields across the country had had more *

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1) protein synthesis

2) selective breeding

3) diffusion

4) breeding of infected plants

3. The Old English Bulldog is extinct. To produce a new English Bulldog, dogs have the desired physical features, but not the aggressive nature of the Old Bulldogs, were mated. The result was a bulldog that was similar in appearance to the extinct bulldog, but without its fierce nature. Which technique was most likely used to develop this new variety of dog? *

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1) cloning

2) mutation

3) genetic engineering

4) selective breeding

4. The diagram below represents the process use in 1996 to clone the first mammal, a sheep named Dolly. Which statement concerning Dolly is correct? *

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1) Gametes from sheep a and sheep B were united to produce Dolly.

2) The chromosome makeup of Dolly is identical to that of sheep A.

3) Both Dolly and sheep C have identical DNA.

4) Dolly contains genes from sheep B and sheep C

5. A scientist claimed that he had cloned a guinea pig to produce two offspring, a male and a female. The claim is not valid because *

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(1) guinea pigs can reproduce both sexually and asexually

(2) the two offspring are not identical copies of the original guinea pig

(3) each of the offspring had half the genetic information of the original guinea pig

(4) none of the genetic information came from the original guinea pig

6. A variety of plant produces small white fruit. A stem was removed from this organism and planted in a garden. If this stem grows into a new plant, it would most likely produce *

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(1) large red fruit, only

(2) large pink fruit, only

(3) small white fruit, only

(4) small red and small white fruit on the same plant

7. Base your answer on the statement below and on your knowledge of biology. *

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(1) selective breeding

(2) genetic engineering

(3) cloning

(4) replication

8. Which statement best describes a population of organisms if cloning is the only method used to reproduce this population? *

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(1) The population would be more likely to adapt to a changing environment.

(2) There would be little chance for variation within the population.

(3) The population would evolve rapidly.

(4) The mutation rate in the population would be rapid.

9. From a single monkey, an animal breeder claims that he has successfully cloned two monkeys. He displays the two monkeys, a male and a female, to the public. The claim of the breeder should be rejected because the monkeys *

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(1) are twins

(2) have the same parents

(3) are of two different sexes

(4) developed from more than one sperm cell

10. Potato farmers in Ireland during the mid-1800s all grew the same type of potato. The potato plants were all produced as clones of one another. When a fungus infected the crop, all of the potatoes were destroyed. This occurred because these potato plants

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(1) had little genetic variability

(2) had increased biodiversity

(3) were the product of fertilization

(4) were the result of biotechnology

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11. Sheep were the first species of mammals to be cloned. Which statement about cloned sheep is correct? *

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(1) Different kinds of body cells in a cloned sheep contain different DNA.

(2) Cloned sheep cannot produce offspring if they are mated with noncloned sheep.

(3) Two sheep cloned from the same parent cannot mate and have offspring.

(4) Many cells in cloned sheep have two identical nuclei, instead of a single nucleus.

12. By which process can a group of Genetically identical plants be rapidly produced from the cells of a single plant? *

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(1) screening

(2) chromosomal karyotyping

(3) Genetic engineering

(4) cloning

13. Modern technology could be used to clone pet dogs and cats. The cloned animals would resemble the original pets because *

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(1) the genes of the new animals are different from those of the original pets

(2) half of the genetic information of the new animals is the same as that of the original pets

(3) the new animals have mutations not found in the original pets

(4) the new animals have the same genetic information as the original pets

14. Several companies now offer DNA “banking services,” where DNA is extracted from a pet and is stored so that a “replacement pet” might be produced using cloning techniques when the original pet dies. Which statement best explains why the replacement pets that are produced in this way might not look or act like the original? *

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(1) The new animal must get the DNA from two different parents, not just one cell.

(2) Mutations could occur that change the cloned animal into a completely different species.

(3) Recombination of the cells as they are cloned will make the resulting pet act differently.

(4) The environment could influence how genes are expressed, changing how the animal looks and acts.

15. Cloning an individual usually produces organisms that *

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(1) contain dangerous mutations

(2) contain identical genes

(3) are identical in appearance and behavior

(4) produce enzymes different from the parent

16. Which process can produce new inheritable characteristics within a multicellular species? *

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(1) cloning of the zygote

(2) mitosis in muscle cells

(3) gene alterations in gametes

(4) differentiation in nerve cells

17. The diagram illustrates a process known as *

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(1) mutation

(2) translocation

(3) cloning

(4) nondisjunction

18. Over the past few thousand years, humans have helped to bring about changes in many plant and animal species in order to make them more useful. Examples include strong workhorses, hunting dogs, large-eared corn, and beautiful flower varieties. These changes were primarily brought about by humans, using the process of *

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(1) mitosis

(2) selective breeding

(3) cloning

(4) mutation

19. Base your answer on the information below and on your knowledge of biology. *

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(1) selective breeding

(2) protein synthesis

(3) cloning

(4) biotechnology

20. Even though identical twins have the same genetic material, they may develop slightly different characteristics because *

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(1) each twin receives different chromosomes from the egg

(2) one twin may only have genes from the father

(3) gene expression may be influenced by factors that switch genes on and off

(4) a gene mutation may have occurred before the zygote divided

21. Will people be able to tell the individuals shown in the picture apart? Why or why not? *

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22. In the United States, there has been relatively little experimentation involving the insertion of genes from other species into human DNA. One reason for the lack of these experiments is that *

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(1) the subunits of human DNA are different from the DNA subunits of other species

(2) there are many ethical questions to be answered before inserting foreign genes into human DNA

(3) inserting foreign DNA into human DNA would require using techniques completely different from those used to insert foreign DNA into the DNA of other mammals

(4) human DNA always promotes human survival, so there is no need to alter it

23. Frequent injections of insulin are often required in order to treat the disorder known as diabetes. Insulin can now be produced in the laboratory through the use of *

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(1) asexual reproduction

(2) artificial selection

(3) sexual reproduction

(4) recombinant DNA

24. To determine the identity of their biological parents, adopted children sometimes request DNA tests. These tests involve comparing DNA samples from the child to DNA samples taken from the likely parents. Possible relationships may be determined from these tests because the *

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(1) base sequence of the father determines the base sequence of the offspring

(2) DNA of parents and their offspring is more similar than the DNA of nonfamily members

(3) position of the genes on each chromosome is unique to each family

(4) mutation rate is the same in closely related individuals

25. This technique used to analyze DNA directly results in *

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