Cloning Animals

Question 1

What are the two methods for cloning animals?

Answer 1

• enucleation and somatic cell nuclear transfer
• artificial embryo training

Question 2

What is enucleation?

Answer 2

• removes nucleus of an egg cell

Question 3

How does enucleation and Somatic Cell Nuclear Transfer work?

Answer 3

• removes a nucleus from a somatic cell (diploid body cell)
• injects somatic nucleus into the enclueated egg cell (same species)
• electric shock - electrofused
• embryo grown in vitro (test tube)
• until embryo spilts (blastocyst)
• embryo inserted into womb of surrogate mother
• embryo genetically identical to parent who donated somatic nucleus.

Question 4

How does artificial embryo training work?

Answer 4

• egg is fertilised in vitro (zygote)
• zygote divides to form an embryo
• unspecialised early embryo cells are separated
  each cell develops into a new embryo
• embryo grows in vitro
• until embryo splits
• embryo is inserted into a womb of surrogate mother
• Embryos genetically identical to each other (No either parents)

Question 5

What are the uses of animal cloning?

Answer 5

• farming - makes exact copies of high yielding phenotypes e.g. high milk yield.
• transformed organisms can be cloned to make useful products e.g. spider silk in milk
• source of embryonic stem cells
• conservation of highly endangered species
• drug research - test subjects are genetically identical - different results are due to drug not genetics

Question 6

What are natural clones?

Answer 6

• occurs naturally
• fertilised egg -> embryo
• embryo splits into two or more cells
• identical twins