Questions vocab

Question 1

DNA methylation

Question 1

Epigenetic phenomenon

Question 2

Cell differentiation

Answer 2

a process in which cells become specialized.

Question 3

Histone proteins

Answer 3

A histone is a positively charged protein that provides structural support for a chromosome. Each chromosome contains a long molecule of DNA, which must fit into the cell nucleus. To do that, the DNA wraps around complexes of histone proteins, giving the chromosome a more compact shape.

The positively charged histones interact with the negatively charged phosphate groups of DNA, forming strong electrostatic bonds.

Question 3

Histone acetyltransferases

Answer 3

zz

Question 4

Enhancer

Question 5

silencer-binding transcription factor

Question 5

an enhancer-binding transcription factor

Question 6

Promoter-proximal-binding transcription factor

Question 7

the TATA-binding protein

Question 8

MicroRNAs

Question 8

Regulatory transcription factors ________.

Answer 8

Influence specific expression of gene

Question 9

Alternative splicing

Answer 9

mRNA processing that leads to different combinations of exons being spliced together

Question 10

RNA interference

Answer 10

It either destroys mRNA
or blocks its translation.

Question 11

Which of the following is most likely to have a small protein called ubiquitin attached to it?

Answer 11

a cyclin protein, which usually acts in G1, in a cell that is in G2

Question 12

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called _____.

Answer 12

RNA itnerference

Question 13

MicroRNAs control gene expression at the level of _______.

Answer 13

translation

These prevent transcribed mRNA from being made into proteins. Either the mRNAs are cut and degraded, or they are blocked from interacting with ribosomes.

Question 14

Predict what would happen to regulation of the lac operon if the lacI gene were moved 50,000 nucleotides upstream of its normal location.

Answer 14

Regulation of the lac operon should be normal.

Question 15

Which of the following statements is about regulation of the lac operon?

Answer 15

A mutation that alters the catabolite activator protein is predicted to alter the regulation of many different operons.

Question 16

There is a mutation in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?

Answer 16

It cannot bind to the inducer.

Question 17

Which of the following would be true in an E. coli cell when glucose concentrations outside the cell are high?

Answer 17

CAP would be transcribed.

Question 18

In lac mutant cells, when there are high levels of glucose present but no lactose, how much -galactosidase will be produced?

Answer 18

A great deal

Question 19

Which choice is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?

Answer 19

Control of both RNA splicing and chromatin remodeling

Question 20

A gene-regulation strategy that is unique to eukaryotic cells is __________.

Answer 20

mRNA processing

Question 21

Which statements about chromatin condensation are incorrect?

Answer 21

An inhibitor of histone deacetylase would promote chromatin condensation.

Chromatin remodeling complexes add chemical groups to histones.

Question 22

Why do histones bind tightly to DNA?

Answer 22

Histones are positively charged, and DNA is negatively charged.

Question 23

In eukaryotes, what allows only certain genes to be expressed in different types of cells?

Answer 23

Different sets of regulatory transcription factors present in each cell

Question 24

How do chromatin-remodeling complexes recognize the genes they should act on? Chromatin-remodeling complexes _____.

Answer 24

recognize specific transcription factors bound to regulatory sequences of DNA