Recombination

Question 1

Process in which a diploid cell becomes haploid

Answer 1

reductive replication

Question 2

What phase does recombination occur ?

Answer 2

It happens during prophase I

Question 3

Crossing over point on chromosome

Answer 3

chiasmata

Question 4

Recombination frequency unit

Answer 4

centimorgang (cM)
1 cM is is distance where recombination id expected to occur 1% if the time per generation.
frequency and physical distance varies depending on locus

Question 5

X and Y genes do not cross except here

Answer 5

The pseudoautosomal region at the tips of the chromosomes

Question 6

2 forms of cancer

Answer 6

familial and sporadic

Question 7

BRCA1 function

Answer 7

has traits of a tumour supressor gene

it is recessive, as both copies must be inactive for cancer to occur

Question 8

3 ways to lose heterozygosity

Answer 8

deletion
where part or the entire chromosome is lost

non dysjunction
where the cell replicates with an uneven chromosome distribution
-endoreduplication - where it has only one chromosome and it duplicates
- chromosome loss, where it has mmp, and p is lost

Question 9

penetrance :

Answer 9

risk of disease for carrier of a gene

Question 10

caretaker vs gatekeeper

Answer 10

CareTaker

• implicated in repair process
• radiation sensitivity of knockouts
• relatively low tumor rate
• associated with DNA repair proteins

GateKeeper

• limited tissue distribution
• acts to suppress growth
• transcriptional regulators
• relatively high penetrance