Use of Biological Resources - Cloning (Paper 2)

Question 1

what is the process of micropropagation?

Answer 1

• in micropropagation, specific plant tissue is selected from stock plant and sterilised
• the tissue sample is then explanted and grown in a petri dish containing sterile nutrient agar gel
• the explant is treated with growth hormones to stimulate development
• the growing shoot can be continuously divided and separated to form new samples
• once the root and shoot are developed, the cloned plant is then transferred to soil, resulting in large quantities of cloned plants expressing identical characteristics to the initial stock plant

Question 2

what are the advantages of micropropagation?

Answer 2

• greater yield
• faster growth
• propagation of a rare species
• can happen at any time of year
• genetic modification can be passed onto the rest of the population efficiently

Question 3

what are the disadvantages of micropropagation?

Answer 3

• the population is genetically identical so is susceptible to disease
• vulnerable to change in conditions
• decreases variation

Question 4

how are mammals cloned?

Answer 4

• a diploid nucleus is extracted from the udder cell of sheep a
• an egg cell is removed from another sheep B and is enucleated
• the diploid nucleus from sheep A is inserted and fused into the enucleated egg cell from sheep B
• the new cell formed is given an electric shock to stimulate cell division via mitosis to form an early embryo which is implanted into the uterus of surrogate

Question 5

what are cloned animals used for?

Answer 5

• cloned transgenic animals can be used to produce human proteins that can help treat diseases
• cloned transgenic animals can also be used to develop organs that will not be rejected by the human immune system in transplants