Question 1

Which of the following best describes the effect of a mutation in a regulatory sequence of a gene?

Accepted Answer

It can alter when, where, or how much protein is made without changing the protein's sequence.

Question 2

A mutation that results in a gene product with reduced but not abolished function is best classified as:

Accepted Answer

Hypomorphic mutation

Question 3

Which type of mutation is most likely to cause a protein to be produced in a tissue where it is not normally expressed?

Accepted Answer

Ectopic expression mutation

Question 4

A temperature-sensitive mutation in a protein causes it to unfold at higher temperatures. This is an example of:

Accepted Answer

Conditional mutation

Question 5

Which of the following is a real-world example of a conditional mutation?

Accepted Answer

A temperature-sensitive mutation in tyrosinase causing Siamese cats to have darker fur at cooler body regions.

Question 6

Which regulatory sequence is most likely to affect the timing of gene expression?

Accepted Answer

Promoter region

Question 7

A mutation that results in a protein with a new function not found in the wild-type is called:

Accepted Answer

Neomorphic mutation

Question 8

If a mutation causes a gene to be expressed at higher levels than normal, it is classified as:

Accepted Answer

Hypermorphic mutation

Question 9

Which of the following best explains why a missense mutation can be temperature-sensitive?

Accepted Answer

It changes the protein's primary sequence, making it unstable at higher temperatures.

Question 10

A mutation in the splice site of a gene could most likely result in:

Accepted Answer

Altered mRNA processing, potentially leading to a nonfunctional protein.

Question 11

Which equation best represents the relationship between gene expression and regulatory sequence activity?

Accepted Answer

$$E = f(R)$$, where $$E is $$gene expression and $$R is $$regulatory sequence activity.

Question 12

A flower with a mutation that results in no pigment production is an example of:

Accepted Answer

Null mutation (loss-of-function)

Question 13

Which of the following scenarios best illustrates a gain-of-function mutation?

Accepted Answer

A gene is expressed in a new tissue, resulting in a novel phenotype.

Question 14

If a mutation in a regulatory sequence causes a gene to be expressed only at low temperatures, this mutation is:

Accepted Answer

Conditional

Question 15

Which of the following is NOT a possible effect of a mutation in a regulatory sequence?

Accepted Answer

Changing the amino acid sequence of the protein.

Question 16

A mutation that destabilizes the secondary and tertiary structure of a protein at lower than normal temperatures is most likely:

Accepted Answer

A conditional mutation

Question 17

Which of the following best describes a hypomorphic mutation?

Accepted Answer

A mutation that reduces but does not eliminate gene function.

Question 18

Which of the following is most likely to result from a mutation in the polyadenylation site of a gene?

Accepted Answer

Impaired mRNA stability and altered protein levels.

Question 19

A mutation that causes a protein to be produced in excess is classified as:

Accepted Answer

Hypermorphic

Question 20

Which of the following best explains why regulatory sequence mutations can have diverse phenotypic effects?

Accepted Answer

They can affect gene expression in terms of timing, location, and amount, leading to varied outcomes.

Genetic Mutations: Regulatory Sequences, Functional Impact, and Conditional Effects

Study Guide - Practice Questions