$$\text{cAMP} + \text{CRP} \rightarrow \text{cAMP-CRP complex}$$

Question 1

Which of the following best describes the function of a repressor in the regulation of gene expression in prokaryotes?

Accepted Answer

A protein that binds to the operator and prevents transcription by blocking RNA polymerase.

Question 2

In the lac operon, which molecule acts as an inducer to turn the operon on, and what is its mechanism?

Accepted Answer

Lactose; it binds to the repressor, inactivating it and allowing transcription.

Question 3

Which of the following best explains the role of histone acetylation in gene expression?

Accepted Answer

Histone acetylation loosens chromatin structure, making DNA more accessible for transcription.

Question 4

A mutation in a proto-oncogene can lead to which of the following outcomes?

Accepted Answer

Formation of an oncogene, which can cause uncontrolled cell growth and division.

Question 5

Which equation best represents the relationship between cAMP and CRP in the activation of the lac operon?

Accepted Answer

$$	ext{cAMP} + 	ext{CRP} ightarrow 	ext{cAMP-CRP complex}$$

Question 6

Which of the following is a real-world example of epigenetic inheritance?

Accepted Answer

A mouse exposed to a high-fat diet has offspring with altered gene expression due to DNA methylation.

Question 7

Which process is most directly responsible for the spatial organization of tissues and organs during embryonic development?

Accepted Answer

Pattern formation

Question 8

A cell receives positional information from morphogens. What is the most likely outcome?

Accepted Answer

The cell will adopt a fate appropriate to its location within the embryo.

Question 9

Which of the following best describes the function of microRNAs (miRNAs) in gene regulation?

Accepted Answer

miRNAs bind to complementary sequences in mRNA, leading to mRNA degradation or inhibition of translation.

Question 10

A fruit fly embryo with a mutation in the bicoid gene will most likely exhibit which phenotype?

Accepted Answer

Abnormal development of the anterior (front) half of the body.

Question 11

Which of the following statements about tumor-suppressor genes is correct?

Accepted Answer

They normally inhibit cell division and prevent uncontrolled cell growth.

Question 12

Which scenario best illustrates the concept of induction during embryonic development?

Accepted Answer

A group of embryonic cells releases signal molecules that cause nearby cells to change their gene expression and differentiate.

Question 13

Which of the following best describes the mechanism of RNA interference (RNAi)?

Accepted Answer

siRNAs bind to mRNA and block gene expression by promoting mRNA degradation.

Question 14

Which equation best represents the effect of DNA methylation on gene expression?

Accepted Answer

$$	ext{DNA} + 	ext{Methyl group} ightarrow 	ext{Reduced transcription}$$

Question 15

A mutation in the P53 gene is most likely to result in which of the following?

Accepted Answer

Failure to suppress the cell cycle, increasing the risk of cancer.

Question 16

Which of the following is a function of control elements in eukaryotic gene regulation?

Accepted Answer

They serve as binding sites for transcription factors that regulate gene expression.

Question 17

Which of the following best describes the role of homeotic genes in development?

Accepted Answer

They control pattern formation in the late embryo, larva, and adult stages.

Question 18

Which scenario best illustrates the concept of alternative RNA splicing?

Accepted Answer

A single gene produces multiple mRNA variants, resulting in different proteins in different tissues.

Question 19

Which of the following best describes the function of the Ras gene in cell signaling?

Accepted Answer

It relays a signal from a growth factor receptor on the cell surface to stimulate cell division.

Regulation of Gene Expression and Developmental Genetics: Key Terms and Concepts

Study Guide - Practice Questions