Chromosomes

Question 1

What does euchromatin contain?

Answer 1

Major genes which need to be transcribe which are easily accessed in DNA

Question 2

What does heterochromatin contain?

Answer 2

Structures which do not need to be accessed regularly in the DNA they are In the tighter loops of DNA

Question 3

What does can methylation do?

Answer 3

Represses gene transcription

Question 4

What is Rett syndrome (RTT)?

Answer 4

Freq 1/10000
Phenotype: childhood neurodevelopmental disorder
Females from 6-18 months have normal development before regression loss of speech purposeful hand movements severe mental retardation
X-linked dominant Xq28 MeCP2 gene gene silencing involved, transcription repression

Question 5

What is immunodeficiency centromeric abnormalities and facial abnormalities (ICF)?

Answer 5

Rare AR disorder mutations in Dnmt3beta preferably methylated CpGs in satellite sequences around centromeres lethal in mice

Question 6

What is the centromeric sequence in yeast?

Answer 6

Simple sequence 120bp 3 domains

Question 7

What is the centromeric sequence in drosophila

Answer 7

Tandem repeats AT rich

Question 8

What is the centromeric sequence in humans?

Answer 8

Alpha-satellite 171bp repeat conserved CENP-B box bond CenpB protein

Question 9

What is the centromeric sequence in mice

Answer 9

Minor satellite, CENP-B box blinds CenpB

Question 10

Telomere function

Answer 10

Natural end of a chromosome, protection, compensation for sequence loss during replication roles in nuclear organisation. DNA sequence conserved in most eukaryotes telomeres

Question 11

Name the subunits of histones

Answer 11

Two lots of H2A, H2B, H3, H4