Lecture 5 - Control of Gene Expression

Question 1

What is condensed chromatin and what type of DNA is in it?

Answer 1

Heterochromatin tends to contain DNA that is transcriptionally inactive as this DNA is often inaccessible to polymerases.

Question 2

What is the term for less condensed chromatin and what type of DNA is usually in it?

Answer 2

Euchromatin contains genes that are typically active in transcription.

Question 3

The presence of methyl groups, particularly in promoter regions is associated with…and is called…

Answer 3

diminished gene expression

hypermethylation

Question 4

The absence of methyl groups on DNA is associated with…and is called…

Answer 4

gene activity

hypomethylation

Question 5

A key mediator of X-inactivation

Answer 5

CpG methylation

Question 6

Deamination of 5-methyl cytosine produces

Answer 6

Thymine

Question 7

Will DNA repair machinery “note” the change in base that occurs from the deamination of 5-methyl cytosine?

Answer 7

No

Question 8

Repressed genes

Answer 8

Inactive LCR, hypoacetylated chromatin, hypermethylation