Biology Chapter 16 Practice Questions

Which of the following are involved in post-transcriptional control? -control of RNA splicing -control of RNA shuttling -control of RNA stability -all of the above

-all of the above

Which of the following are true of epigenetic changes? -allow DNA to be transcribed -move histones to open or close a chromosomal region -are temporary -all of the above

-all of the above

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

Alternative splicing creates shorter mRNA transcripts.

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

Cells can become specialized within a multicellular organism. Organisms can conserve energy and resources.

The binding of ________ is required for transcription to start.

RNA polymerase

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

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

The ara operon is an inducible operon that controls the production 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) ________.

activator

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

all expressed, all of the time transcribed and translated almost simultaneously transcriptionally controlled because translation begins before transcription ends

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

either increase or decrease

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

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

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

increased transcription of a distant gene

Cancer causing genes are called ________.

oncogenes

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?

patients with lots of the estrogen receptor expressed in their tumor

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

protein function

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

regressed

Post-translational control refers to:

regulation of gene expression after translation

What are epigenetic modifications?

the addition of reversible changes to histone proteins and DNA