Question 1

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

Accepted Answer

DNA is transcribed into mRNA, which is then translated into protein.

Question 2

A frameshift mutation is most likely to result from which of the following events?

Accepted Answer

Insertion or deletion of one or more nucleotide pairs.

Question 3

Which equation best represents the direction of DNA synthesis during replication?

Accepted Answer

$$5' \rightarrow 3'$$

Question 4

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

Accepted Answer

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

Question 5

Which of the following is a consequence of a nonsense mutation?

Accepted Answer

A stop codon is introduced, resulting in premature termination of translation.

Question 6

Which of the following statements about bacterial chromosomes is correct?

Accepted Answer

Bacteria usually have a single circular chromosome made of DNA.

Question 7

What is the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments on the lagging strand.

Question 8

Which of the following is true about the genetic code?

Accepted Answer

It is degenerate, meaning multiple codons can code for the same amino acid.

Question 9

Which of the following best describes a repressible operon?

Accepted Answer

Structural genes are transcribed until they are turned off by a corepressor.

Question 10

Which of the following is a real-world consequence of bacterial gene alteration?

Accepted Answer

Antibiotic resistance can develop, making infections harder to treat.

Question 11

Which of the following is NOT a function of plasmids in bacteria?

Accepted Answer

Encoding ribosomal RNA for protein synthesis.

Question 12

Which of the following is a mechanism of horizontal gene transfer in bacteria?

Accepted Answer

Conjugation via sex pili.

Question 13

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

Accepted Answer

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

Question 14

Which of the following is a chemical mutagen that causes base pairing mistakes?

Accepted Answer

Nucleoside analogs.

Question 15

Which of the following is the correct formula for calculating mutation rate?

Accepted Answer

$$	ext{Mutation rate} = \frac{	ext{Number of mutations}}{	ext{Total number of cell divisions}}$$

Question 16

Which of the following is a method used to identify chemical carcinogens using bacteria?

Accepted Answer

Ames test.

Question 17

Which of the following statements about transposons is correct?

Accepted Answer

Transposons are segments of DNA that can move from one region of DNA to another.

Question 18

Which of the following is a result of UV radiation on bacterial DNA?

Accepted Answer

Formation of thymine dimers.

Question 19

Which of the following is true about the process of transcription in prokaryotes?

Accepted Answer

Transcription begins when RNA polymerase binds to the promoter sequence on DNA.

Question 20

Which of the following best describes the outcome of genetic recombination in bacteria?

Accepted Answer

New combinations of genes are formed, contributing to genetic diversity.

Microbial Genetics: Structure, Function, and Regulation of Genetic Material

Study Guide - Practice Questions