AD3

Question 1

Briefly describe Dolly the sheep experiment

Answer 1

• First mammal cloned from adult cells
• Adult sheep mammary gland cells were deprived of growth factor and fused with enucleated eggs and transplanted into a surrogate

Question 2

What is significant about the sheep Megan and morag?

Answer 2

The first mammals cloned from cultured differentiated cells

Question 3

What are 2 features that allow cloning by nuclear transfer?

Answer 3

1) Nucleus of every somatic cell contains 2 complete copy of the individuals genome
2) A fertilised egg is totipotent

Question 4

Give 3 reasons why cloning by somatic cell nuclear transfer is controversial?

Answer 4

1) Invasive
2) There are technical problems
3) Ethical dilemma

Question 5

What are 2 examples of natural cloning?

Answer 5

1) Asexual reproduction

2) When 2 blastomeres seperate naturally eg. monozygotic twins

Question 6

What are the 4 mechanisms of cloning?

Answer 6

1) Natural
2) Embryo splitting
3) Reprogramming somatic cells
4) Nuclear transfer

Question 7

What is a clone?

Answer 7

An individual that is genetically identical to another individual

Question 8

How can stem cells be used to treat Parkinsons disease?

Answer 8

Embryonic stem cells can be induced to produce dopamine which is missing in patients with Parkinson’s disease

Question 9

In mice what do stem cells differentiate in response to?

Answer 9

Cytoplasmic signals

Question 10

5 problems with cloning

Answer 10

1) Telomeres shorten- age faster
2) Large foetus syndrome and prolonged pregnancy
3) Low success rate
4) Lack of genetic variation= disease vulnerability
5) Physiological problems for human cloning

Question 11

2 problems with conservation cloning?

Answer 11

1) Who decides which species should be cloned

2) Doesnt address the problem of habitat loss