Regulation of Gene Expression

Question 1

Bacteria can respond to environmental change by

Answer 1

*Regulating protein activity
*Regulating protein production

Question 2

An operon in bacteria is a stretch of DNA that includes

Answer 2

*Promoter
*Operator
*The genes that they control

Question 3

Operator

Answer 3

DNA within promoter that acts as a regulatory “switch”

Question 4

Negative gene regulation
What is the involvement of a repressor

Answer 4

*Repressible operons
*Inducible operons

Question 5

Repressible Operon

Answer 5

A repressible operon is usually on; binding of a repressor to the operon shuts off transcription

Question 6

Positive gene regulation

Answer 6

Some operons are also subject to positive control

Question 7

If lactose is present and glucose is scarce with cAMP level high what are the results?

Answer 7

Abundant lac mRNA synthesized

Question 8

If lactose is present and glucose is present with cAMP level low what are the results?

Answer 8

Little lac mRNA synthesized

Question 9

What is CAP

Answer 9

catabolite activator protein

Question 10

Combined negative and positive regulation in E.coli

Answer 10

*lac repressor acts as on/off switch
*CAP acts as volume control

Question 11

All organisms must regulate which _____ are expressed at any given time

Answer 11

Genes

Question 12

In multicellular organisms what is essential for cell specialization?

Answer 12

Gene expression

Question 13

True or false
Eukaryotic gene expression can be regulated only at certain stages.

Answer 13

False
It can be regulated at every stage.

Question 14

Are cells in an organism genetically identical?

Answer 14

Yes

Question 15

Differences between cell types result from what?

Answer 15

Differential gene expression

Question 16

What does acetylation of histone tails promote?

Answer 16

Loose chromatin structure that permits transcription.

Question 17

Do histone tails protrude inward or outward from a nucleosome?

Answer 17

Outward

Question 18

Epigenetic Inheritance

Answer 18

The inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence.

Question 19

Chromatin Modifications

Answer 19

*Do not alter DNA sequence
*….but may be passed to future generations of cells

Question 20

Control Elements

Answer 20

Segments of noncoding DNA that help regulate transcription by binding certain proteins.

Question 21

True or False
Control elements are critical to the precise regulation of gene expression in different cell types.

Answer 21

True

Question 22

Does RNA polymerase require general transcription factors to initiate transcription in eukaryotes

Answer 22

Yes

Question 23

What do high levels of transcription of particular genes depend on?

Answer 23

Specific transcription factors