Question 1

Which process describes the synthesis of RNA from a DNA template?

Accepted Answer

Transcription

Question 2

A mutation that changes a codon but does not alter the amino acid sequence of the resulting protein is called:

Accepted Answer

Silent mutation

Question 3

Which of the following best describes a frameshift mutation?

Accepted Answer

An insertion or deletion of nucleotides that alters the reading frame

Question 4

Which equation best represents the spontaneous mutation rate per replicated gene?

Accepted Answer

$$10^{-6}$$

Question 5

Which of the following is NOT a mechanism by which bacteria can resist antibiotics?

Accepted Answer

Increasing the permeability of the cell membrane to the drug

Question 6

A hospital patient is prescribed antibiotics for a viral infection and does not complete the full course. What is the most likely consequence?

Accepted Answer

Increased risk of developing antibiotic resistance in bacteria

Question 7

Which of the following statements about the lac operon is correct?

Accepted Answer

Lactose acts as an inducer, inactivating the repressor and turning the operon on

Question 8

Which of the following is an example of horizontal gene transfer in bacteria?

Accepted Answer

Transfer of plasmid DNA via conjugation

Question 9

A chemical mutagen increases the mutation rate from $$10^{-6} to$$ $$10^{-3}$$ per replicated gene. What is the fold increase in mutation rate?

Accepted Answer

$$10^3-$$fold

Question 10

Which of the following best describes the role of a corepressor in a repressible operon?

Accepted Answer

It binds to the repressor protein, activating it to inhibit transcription

Question 11

Which of the following is a correct statement about transformation in bacteria?

Accepted Answer

It involves uptake of free DNA from the environment

Question 12

Which of the following is a plausible consequence of using antibiotics in animal feed?

Accepted Answer

Increased probability of selecting for resistant mutants

Question 13

Which of the following best describes conjugation in bacteria?

Accepted Answer

Transfer of plasmid DNA via direct cell-to-cell contact

Question 14

Which of the following is NOT a misuse of antibiotics?

Accepted Answer

Using narrow spectrum antibiotics for a confirmed bacterial infection

Question 15

Which of the following is a correct description of a missense mutation?

Accepted Answer

A mutation that changes one amino acid in the protein sequence

Question 16

Which of the following is a function of plasmids in bacteria?

Accepted Answer

Encoding genes for antibiotic resistance

Question 17

Which of the following is a method to combat microbial resistance?

Accepted Answer

Tracking resistance data nationwide

Question 18

Which of the following statements about the tryptophan operon is correct?

Accepted Answer

Tryptophan acts as a corepressor, activating the repressor to turn the operon off

Question 19

Which of the following is the correct sequence of events in gene expression?

Accepted Answer

DNA replication → transcription → translation

Question 20

A bacterium acquires a plasmid carrying a gene for beta-lactamase. What is the most likely outcome?

Accepted Answer

The bacterium becomes resistant to beta-lactam antibiotics

Chapter 8: Genetics – Mutations, Gene Expression, and DNA Transfer in Microbiology

Study Guide - Practice Questions