Cloning Animals

Question 1

What are the 3 types of cloning in animals?

Answer 1

enucleation and somatic cell nuclear transfer

artificial embryo twinning

natural clones

Question 2

What happens during enucleation and somatic cell nuclear transfer?

Answer 2

• enucleate - remove nucleus from an egg cell
• remove a nucleus from a somatic cell - gamete (diploid body cell)
• inject the somatic nucleus into the enucleated egg cell - as long as it is the
  same species
• electric shock - electrofused
• embroyo is grown in a vitro - test tube
• this is until the embroyo splits - blastocyst
• embroyo is inserted into the womb of a surrogate mother
  -embroyo genetically identical to parent who donated somatic nucleus

Question 3

What happens during artificial embryo twinning?

Answer 3

• egg is fertilised in vitro to form a zygote
• zygote divides to form an embryo
• unspecialised early embryo cells are separated
• each embroyo cell can develop into a full embryo
• embroyos grown in vitro
• this happens until embryo splits
• embryo inserted into the womb of surrogate mother
• embryo genetically identical to each other

Question 4

What happens during natural clones?

Answer 4

• occurs naturally
• happens when a fertilised egg becomes an embryo and splits
  into 2 or more cells
• this is the formation of identical twins

Question 5

What are the uses of animal cloning?

Answer 5

• farming - make exact copies of high yielding phenotypes e.g. high milk yield
• make transformed organisms can be cloned to make useful products. e.g. spider silk in milk
• source of embryonic stem cells - totipotent or pluripotent
• conservation of highly endangered species
• drug research - test subjects are genetically identical - different results due to drug