Final Gene Control Practice

Operons are found in the cells of which of the following types of organisms?

• prokaryotes

• eukaryotes

• animals only

• viruses

The "on/off" switch for an operon is called the

• promoter

• enhancer

• operator

• gene

What is a gene?

• A segment of RNA that encodes for a protein

• The portion of the chromosome that does not get transcribed

• A segment of DNA that encodes for a protein

• The collection of your chromosomes

A small molecule that binds to a repressor and makes it active

• repressor

• regulator

• activator

• corepressor

The tryptophan operon is

• permanently turned on.

• turned on when tryptophan is present in the growth medium.

• turned off only when glucose is present in the growth medium.

• turned off when tryptophan is added to the growth medium.

RNA polymerase needs --- to initiate transcription.

• holoenzymes

• transcriptional factors

• histones

• microRNA

The human genome appears to have only about as many genes as the simple nematode worm, C. elegans. Which of the following best explains how the more complex humans can have relatively few genes?

• Human genes have unusually long introns involved in the regulation of gene expression

• More than one polypeptide can be produced from a gene by alternative gene splicing

• The human genome has a high proportion of noncoding DNA

• The human genome has a large number of SNPs (single nucleotide polymorphisms) which increases genetic variability

Tags

IST-2

Which of the following help to turn genes on so that they are expressed (transcribed and translated)?

• a high level of condensation (coiling around histones)

• histone acetylation

• DNA methylation

• histone methylation

One way to regulate the expression of a gene is to control the formation of mRNA. This is called ___ control.

• transcriptional

• translational

• post-transcriptional

• post-translational

Which of the following is/are similarities between prokaryotic and eukaryotic gene expression?

• both use proteins to interact with the DNA to control gene expression

• both have histones complexed with their DNA

• both separate the processes of transcription and translation spatially

• all of the above