Question 1

Which of the following best describes the function of DNA polymerase during DNA replication?

Accepted Answer

It synthesizes new DNA strands by adding nucleotides to a pre-existing strand.

Question 2

During transcription in eukaryotes, which of the following is the correct sequence of events?

Accepted Answer

Initiation, elongation, termination

Question 3

A mutation occurs in the promoter region of a gene. What is the most likely effect on gene expression?

Accepted Answer

Transcription may decrease or stop due to reduced RNA polymerase binding.

Question 4

Which of the following equations correctly represents the Hardy-Weinberg equilibrium for allele frequencies in a population?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 5

A virus with a lytic life cycle infects a host cell. What is the most likely outcome for the host cell?

Accepted Answer

The host cell will be lysed, releasing new viral particles.

Question 6

Which of the following is a direct result of DNA methylation in eukaryotic cells?

Accepted Answer

Decreased transcription of methylated genes

Question 7

In the lac operon of E. coli, what happens when lactose is present and glucose is absent?

Accepted Answer

The operon is activated and enzymes for lactose metabolism are produced.

Question 8

Which of the following best explains why Okazaki fragments are formed during DNA replication?

Accepted Answer

DNA polymerase can only synthesize DNA in the 5' to 3' direction.

Question 9

A patient is diagnosed with a genetic disease caused by a point mutation in a tumor-suppressor gene. What is the most likely consequence?

Accepted Answer

Uncontrolled cell division leading to cancer

Question 10

Which of the following is a function of microRNA (miRNA) in eukaryotic cells?

Accepted Answer

Regulating gene expression by interfering with mRNA translation

Question 11

A scientist uses CRISPR-Cas9 to edit a gene in a plant. What is the primary mechanism by which CRISPR-Cas9 achieves gene editing?

Accepted Answer

It introduces a double-strand break at a specific DNA sequence.

Question 12

Which of the following best describes the role of ribosomal RNA (rRNA) in translation?

Accepted Answer

It forms the core structure of the ribosome and catalyzes peptide bond formation.

Question 13

During alternative RNA splicing, what is the result for the final mRNA product?

Accepted Answer

Multiple mRNA variants can be produced from a single gene.

Question 14

Which of the following is true about the structure of viral genomes?

Accepted Answer

Viral genomes can be composed of DNA or RNA, single or double stranded.

Question 15

A stem cell is described as pluripotent. What does this mean?

Accepted Answer

It can differentiate into any cell type in the body.

Question 16

Which of the following is a key difference between the lytic and lysogenic cycles of bacteriophages?

Accepted Answer

The lysogenic cycle allows the virus to remain dormant within the host genome.

Question 17

Which equation would you use to calculate the frequency of heterozygotes in a population under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq$$

Question 18

A researcher observes that a gene is highly expressed in liver cells but not in skin cells. Which regulatory mechanism is most likely responsible?

Accepted Answer

Epigenetic modifications such as histone acetylation

Question 19

Which of the following is a real-world application of stem cell technology?

Accepted Answer

Regenerating damaged tissues in patients with spinal cord injuries

Question 20

A scientist is studying the effect of RNA interference (RNAi) on gene expression. What is the expected outcome when RNAi is active?

Accepted Answer

Decreased expression of target gene due to mRNA degradation

General Biology II: Molecular Genetics, Gene Expression, Viruses, and Biotechnology – Study Guide

Study Guide - Practice Questions