Gene Regulation I and II

Question 1

What effect does DNA methylation have on genes?

Answer 1

Inactivates genes

Question 2

Demethylation of DNA will _____ genes.

Answer 2

activate

Question 3

What is the histone acetylation effect on genes?

Answer 3

Activates genes

Question 4

Most genes are silenced in _______ unless needed to be turned on.

Answer 4

Eukaryotes

Question 5

Silent for of the chromatin:

Answer 5

heterochromatic

Question 6

Why is heterochromatin silenced?

Answer 6

Bc:

1. DNA in hypermethylation at CpG islands
2. Histones are deacetylated.

Question 7

Define euchromatin:

Answer 7

Active form of chromatin that is transcribed.

Question 8

What type of chromatin has hypomethylated DNA and acetylated histones?

Answer 8

Euchromatin

Question 9

Define epigenetics.

Answer 9

Changes in the phenotype without changes in genotype.

Question 10

Silenced genes have _____ DNA.

Answer 10

Methylated

Question 11

Active genes have ____ histones.

Answer 11

Acetylated

Question 12

DNA methylation occurs at _____.

Answer 12

CpG islands

Question 13

Repressor proteins are attracted to _______.

Answer 13

Methylcytosines

Question 14

Dosage compensation is managed by:

Answer 14

Different DNA methylation patterns in male and female gametes

Question 15

Genomic imprinting Dz examples:

Answer 15

Prader-Willi Syndrome

Angelman Syndrome

Question 16

Chromosome 15 deletion is involved in these Dz.

Answer 16

Prader-Willi Syndrome

Angelman Syndrome

Question 17

If mutant chromosome 15 is inherited from father, only maternal genes from that region are expressed. What Dz is this?

Answer 17

Prader-Willi Syndrome

Question 18

In Angelman Syndrome, _____ chromosome 15 is the mutant.

Answer 18

maternal

Question 19

Whose genes are expressed in Prader-Willi Syndrome?

Answer 19

Maternal genes are expressed

Question 20

When only the paternal genes are expressed on chromosome 15:

Answer 20

Angelman Syndrome

Question 21

Methyls for DNA methylation come from:

Answer 21

SAM

Question 22

What are the classes of Transcription Factors?

Answer 22

• Basal factors
• Activators
• Mediators
• Repressors
• Chromatin modifiers

Question 23

Name a Helix-Turn-Helix Transcription factor domain:

Answer 23

Homeodomain proteins

Question 24

Steroid hormone receptors are what type of Transcription Factors?

Answer 24

Zinc Finger

Question 25

What do Leucine Zippers do?

Answer 25

Involved in protein-protein interactions.

They dimerize.

Question 26

Fxn of Activation domain Transcription factors:

Answer 26

-Interact with RNA polymerase

Question 27

In highly acidic or glutamine-rich regions, you will find _______ Transcription Factors.

Answer 27

Activation Domains

Question 28

What do microRNAs do generally?

Answer 28

Mediate the silencing of many genes

Question 29

How do the microRNAs mediate the silencing of genes?

Answer 29

• Interact with mRNA by causing mRNA degradation OR inhibition of translation
• formation of heterochromatin

Question 30

When interacting with mRNA, defective dicer microRNAs can cause _______ in the eyes.

Answer 30

Retinal degeneration

Question 31

Eye development involves signaling between these tissue layers.

Answer 31

Mesenchyman and epithelial