L6 - cell growth, mitosis, meoisis

Question 1

Structural components of mitosis :

- chromosome:

Answer 1

Centromere: middle of chromosome

4 stalks : chromatid

Kinetochore; complex of proteins that bind to microtubule spindle

Centrosome : organelle that acts as a microtubule organising centre during mitosis

Question 2

Regulation of cell cycle :
What regulates it?
Is it specific?

Answer 2

Cyclins bind to Cdk’s: cyclin dependent kinases
They regulate expression of or function of key proteins in each stage of cell cycle

Cdk’s that cyclin bind to are specific to each stage of cell cycle
Eg
G1 : go or no go
S : is environment favourable
G2 : has all DNA been rep,I acted & any damaged DNA repaired?
M: are all chromosomes attached to mitotic spindle

Question 3

Apoptosis

Answer 3

Programmed cell death.

Question 4

Recombination

Answer 4

Chromatids are no longer identical as they have swapped some genetic material between them