5. eukaryotic genome organisation

Question 1

what is the major protein component of chromatin?

Answer 1

Histone

Question 2

What does chromatin exist as in interphase?

Answer 2

10% active euchromatin
80% inactive euchromatin
10% heterochromatin

Question 3

Which histone molecules does the nucleus contain?

Answer 3

2 x H2A H2B H3 and H4

1 x H1

Question 4

how does the histone octamer form?

Answer 4

H3-H4 tetramer bound with two H2A-2B dimers

Question 5

what are high mobility group proteins implicated in?

Answer 5

global regulation of transcription

Question 6

Which three functional elements does chromosome replication and stability require?

Answer 6

telomere, origin of replication and centromere

Question 7

How does the origin of replication work?

Answer 7

ORC binds - Cdc6 and Cdt1 bind - Mcm helicase binds - Cdc 6 and ORC are phosphorylated and the helicase opens up the helix for replication

Question 8

Which two types of chromatin are found in the centromere?

Answer 8

1. chromatin containing normal histone H3 that is dimethylated at lysine 4
2. chromatin containing centromere specific histone H3 variant

Question 9

What is the vertebrate telomere sequence?

Answer 9

TTAGG