Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA $$ \rightarrow $$ RNA $$ \rightarrow $$ Protein

Question 2

A mutation that results in the insertion or deletion of one or more nucleotide pairs, causing a shift in the reading frame, is called:

Accepted Answer

Frameshift mutation

Question 3

Which enzyme is responsible for unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Question 4

In the lac operon, what happens when lactose is present in the environment?

Accepted Answer

Allolactose (inducer) binds to the repressor, inactivating it and allowing transcription.

Question 5

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids are self-replicating circular DNA molecules that can carry antibiotic resistance genes.

Question 6

Which process describes the transfer of genetic material from one bacterial cell to another via a bacteriophage?

Accepted Answer

Transduction

Question 7

What is the role of cAMP in the regulation of the lac operon?

Accepted Answer

cAMP binds to the catabolite activator protein (CAP), which then binds to the promoter to enhance transcription when glucose is low.

Question 8

Which of the following best describes a repressible operon?

Accepted Answer

It is always on unless a corepressor is present to activate the repressor.

Question 9

A base substitution mutation that results in a stop codon is called a:

Accepted Answer

Nonsense mutation

Question 10

Which of the following is a function of DNA polymerase during DNA replication?

Accepted Answer

Synthesizes new DNA strands and proofreads for errors

Question 11

Which of the following best explains why mutations are important for evolution?

Accepted Answer

Mutations and recombination create genetic diversity, which is the raw material for natural selection.

Question 12

Which of the following is a method used to repair thymine dimers caused by UV radiation?

Accepted Answer

Photolyase uses visible light energy to separate thymine dimers.

Question 13

Which of the following is TRUE about horizontal gene transfer?

Accepted Answer

It involves the transfer of genes between cells of the same generation.

Question 14

Which of the following best describes the function of tRNA during translation?

Accepted Answer

tRNA transports amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 15

Which of the following is a real-world application of genomics in medicine?

Accepted Answer

Using genomics to design personalized cancer therapies based on a patient's genetic profile.

Question 16

Which of the following is a correct statement about the difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

In eukaryotes, transcription occurs in the nucleus and translation in the cytoplasm.

Question 17

Which of the following best describes the Ames test?

Accepted Answer

It exposes mutant bacteria to mutagenic substances to measure the rate of reversal of the mutation.

Question 18

Which of the following is a function of transposase?

Accepted Answer

Cuts DNA backbone, leaving single-stranded 'sticky ends'

Question 19

Which of the following is a likely consequence of a nonsense mutation in a gene?

Accepted Answer

The protein is truncated due to the introduction of a premature stop codon.

Microbial Genetics: Structure, Function, and Regulation

Study Guide - Practice Questions