Chapter 16

Question 1

Control of gene expression in eukaryotic cells occurs at which level(s)?

Answer 1

epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels

Question 2

Post-translational control refers to:

Answer 2

regulation of gene expression after transcription

Question 3

how does the regulation of gene expression support continued evolution of more complex organisms?

Answer 3

Both A and B

Question 4

If glucose is absent, but so is lactose, the lac operon will be

Answer 4

repressed

Question 5

Prokaryotic cells lack a nucleus. Therefore, the genes in prokaryotic cells are:

Answer 5

B and C are both true

Question 6

The ara operon is an inducible operon that controls the breakdown of the sugar arabinose. When arabinose is present in a bacterium it binds to the protein AraC, and the complex binds to the initiator site to promote transcription. In this scenario, AraC is a(n) _______.

Answer 6

activator

Question 7

What are epigenetic modifications?

Answer 7

the addition of reversible changes to histone proteins and DNA

Question 8

Which of the following are true of epigenetic changes?

Answer 8

all of the above

Question 9

The binding of _____ is required for transcription to start.

Answer 9

RNA polymerase

Question 10

What will result from the binding of a transcription factor to an enhancer region?

Answer 10

increased transcription of a distant gene

Question 11

A scientist compares the promoter regions of two genes. Gene A’s core promoter plus proximal promoter elements encompasses 70bp. Gene B’s core promoter plus proximal promoter elements encompasses 250bp. Which of the scientist’s hypothesis is most likely to be correct?

Answer 11

Transcription of Gene A involves fewer transcription factors.

Question 12

Which of the following are involved in post-transcriptional control?

Answer 12

all of the above

Question 13

Binding of an RNA binding protein will ______ the stability of the RNA molecule.

Answer 13

either increase or decrease

Question 14

An unprocessed pre-mRNA has the following structure. Which of the following is not a possible size (in bp) of the mature mRNA?

Answer 14

250bp

Question 15

Alternative splicing has been estimated to occur in more that 95% of multi-exon genes. Which of the following is not an evolutionary advantage of alternative splicing?

Answer 15

Alternative splicing creases shorter mRNA transcripts.

Question 16

Post-transitional modifications of proteins can affect which of the following?

Answer 16

protein function

Question 17

A scientist mutates eIF-2 to eliminate it GTP hydrolysis capability. How would this mutated form of eIF-2 alter translation?

Answer 17

The large ribosomal subunit would not be able to interact with mRNA transcripts.

Question 18

Cancer causing genes are called _____.

Answer 18

oncogenes

Question 19

Targeted therapies are used in patients with a set gene expression pattern. A targeted therapy that prevents the activation of the estrogen receptor in breast cancer would be beneficial to which type of patient?

Answer 19

patient with lots of estrogen receptors expressed in their tumor