S9: Cloning

Question 1

What are clones?

Answer 1

Genetically identical individuals, formed by organisms asexually reproducing.

Question 2

Are identical twins clones?

Answer 2

Yes, but they must be identical twins. This is an example of natural clones in animals.

Question 3

Describe the process of animal cloning?

Answer 3

1. The diploid nucleus, from a body cell of the organism being cloned is removed from the cell.
2. It is inserted into a enucleated egg cell (egg cell with its nucleus removed) from the surrogate mother
3. A short burst of electricity is used to stimulate the egg with the nucleus to start dividing by mitosis#
4. The embryo is implanted into the surrogate mother’s uterus.

Question 4

How can cloning and genetic modification be used together for human benefit?

Answer 4

We can genetically modify animals to produce large quantities of drugs for humans, or other beneficial material. These animals can be cloned to increase the population of animals that produce the product quickly.

Question 5

What are the advantages of cloning?

Answer 5

Production of large amounts of human specific proteins
No risk of rejection as antigens/ proteins will be human

Question 6

What are the disadvantages of cloning?

Answer 6

Takes a long time to carry out the process
Expensive
Not ethical in terms of animal rights
Protein can’t be harvested for a long time, until lactation, from when the organism is born.

Question 7

What is xenotransplantation?

Answer 7

The transplantation of organs and tissues into members of different species, e.g. pig heart into a human.

Question 8

How does xenotransplantation get carried out?

Answer 8

animals, e.g. pigs are genetically modified to produce human marker antigens on their cell surface membrane. and therefore would be less likely to be rejected by a recipient.

Question 9

What is micropropagation?

Answer 9

Cloning plants by taking cuttings, so that they are genetically identical to the parent plant.

Question 10

What are explants?

Answer 10

Usually small tissues are taken from the stem or the shoot - these are called explants

Question 11

Describe the process of micropropagation

Answer 11

1. The explants and equipment are sterilized to remove any contaminants, like pathogens
2. They are then placed in a sterile agar jelly which contains nutrients that are needed for the plant to grow (nitrates, magnesium, auxin, amino acids)
3. The light intensity, CO2 conc. , humidity and temp are controlled for optimum growing conditions.
4. after the explants have grown roots, the plantlets are placed in compost to grow.

Question 12

What are the advantages of micropropagation?

Answer 12

Large numbers of genetically identical plants can be grown at once

Species that are difficult to grow from seeds or cuttings alone can be grown

Plants can be produced any time of year

Large numbers of plants can be stored easily

GM can be introduced into thousands of plants quickly.