Lecture 2

Question 1

what are the phases of mitosis and what happens in each

Answer 1

prophase - condensation of sister chromatids
metaphase - attachment of mitotic spindle to kinetochore
anaphase - seperation of sister chromatids to each pole
telophase - nuclear envelope reassembly

Question 2

what is is called when we use Xenopus oocytes to study mitosis

Answer 2

cell free mitosis

Question 3

what cyclin drives entry into mitosis

Answer 3

M-Cdk
causes assembly of spindle
chromosome condensation
breakdown of nuclear envolope
rearrangement of cytoskeleton and Golgi
levels increase through G2 and M

Question 4

what are the 2 targets of anaphase promoting complex i.e. ubiquitin ligase

Answer 4

1. securin - holds sister chromatids together

2. S and M cyclins

Question 5

what is it called when you lose an allele

Answer 5

heteropzygosity

Question 6

what are the three types of mitotic spindle

Answer 6

interpolar spindle - overlap
kinetochore spindle - attach chromosomes
astral - position spindle

Question 7

how are inappropriate attachments of spindle sensed

Answer 7

tension
correct = pulled in opposite direction
incorrect = lower tension that causes inhibitory signals

Question 8

what activates APC

Answer 8

Cdc20

Question 9

how do you lode homozygosity in mitosis

Answer 9

nondisjunction

gene conversion

Question 10

describe gene conversion

Answer 10

DNA polymerase jumps between strands