animal cloning

Question 1

How do some invertebrates clone themselves?

Answer 1

starfish regenerate entire animals from fragments of the original one if damaged, hydra produce small buds on the side of their body which develops into identical clones

Question 2

How can vertebrates naturally clone?

Answer 2

twins - random splitting of early embryo forming two separate ones which develop into genetically identical foetuses

Question 3

What are the two types of artificial cloning?

Answer 3

artificial embryo twinning and somatic cell nuclear transfer

Question 4

Explain the process of artificial embryo twinning in cows?

Answer 4

treat cow with hormones causing it to super ovulate, eggs can be fertilised naturally or artificially inseminated using a bull with desirable traits, early embryos are then flushed out the uterus, around day 6 of the embryos life while cells are still totipotent, the embryo is split producing several smaller embryos, each is initially grown in a lab to make sure all is well and then place into a surrogate mother, each embryo in a different cow as single pregnancies are safer, foetuses develop and identical cows are born all from different mothers

Question 5

How does somatic cell nuclear transfer work?

Answer 5

somatic cell is taken from sheep A, nucleus is extracted and kept, an unfertilised egg is taken from sheep B and nucleus is removed forming an enucleated egg, nucleus from somatic cell is inserted into enucleated egg and fused using a mild electric shock which also triggers mitosis and an embryo is produced, embryo is implanted into a surrogate mother and a lamb is born that is a clone of sheep A bar the mitochondrial DNA which comes from egg of sheep B

Question 6

What are the uses of animal cloning?

Answer 6

drug research, save endangered species, pass on desirable characteristics, cloning GM animals, high yielding farm animals to produce more offspring

Question 7

What are the pros of animal cloning?

Answer 7

high yielding farm animals can be cloned, infertile animals can reproduce, GM animals can be cloned, desirable traits can be kept (race horses), no waiting for breeding seasons as it can be done at anytime, biodiversity can be preserved as endangered species can be saved

Question 8

What are the reasons against cloning?

Answer 8

difficult, time consuming, expensive, not a full proof process, animals produced through cloning have generally had a shortened life span, no genetic variation, ethically controversial