Cloning in animals Flashcards
1
Q
How does cloning occur in vertebrates?
A
- most commonly forming monozygotic twins (identical twins).
- early embryo splits to form seperate embryos
- frequency depends on species
- identical twins may look different due to different position and nutrition in the uterus
- some amphians and reptile produce offspring when no male is available.
- offspring often male, so not clones of mother, yet all genetic information arises from her
2
Q
How are totipotent cells formed?
A
- after egg is fertilised, it divides to from a ball of totipotent cell
3
Q
What is the significance of totipotent cells?
A
has potential to form a new entire embryo
4
Q
What happens in artificial twinning?
A
- early embryo manually split into (potentially) many pieces
5
Q
What is artificial twinning used for
A
by farming community to produce maximum offspring from particularly good dairy or beef cattle or sheep
6
Q
How is the parents selected and prepared for artificial twinning?
A
- desireable traits
- female treated with hormones so she super-ovulates, releasing more mature ova than normal
7
Q
What happens to the ova?
A
- may be fertilised naturally or by artifical insemnation
- from a male with good traits
- early embryo gently flushed out of uterus
- or ova removed and fertilised by quality semen in the lab
8
Q
When is the embryo split?
A
before or around day six
9
Q
What happens to the split embryo?
A
- grown in lab for a few days to ensure all is well before it is implanted into a surrogate mother
- each embryo is implanted into a different mother (as many are implanted as the species would normally produce)
