Question 1

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

Accepted Answer

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

Question 2

A mutation changes a codon from UAU (tyrosine) to UAA (stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 3

Which enzyme is responsible for synthesizing the new DNA strand during replication in prokaryotes?

Accepted Answer

DNA polymerase

Question 4

A bacterium is found to grow optimally at 70°C. How would you classify this organism based on temperature preference?

Accepted Answer

Thermophile

Question 5

Which of the following statements about operons is correct?

Accepted Answer

An operon is a cluster of genes under the control of a single promoter and operator.

Question 6

During translation, which molecule brings amino acids to the ribosome?

Accepted Answer

tRNA

Question 7

A patient develops an infection after surgery in a hospital. This infection is best described as:

Accepted Answer

Healthcare-associated infection (HAI)

Question 8

Which of the following best explains why bacteria can simultaneously transcribe and translate a gene, but eukaryotes cannot?

Accepted Answer

Bacteria lack a nuclear membrane, allowing ribosomes to access mRNA as it is being transcribed.

Question 9

Which of the following is a chemical requirement for microbial growth?

Accepted Answer

Carbon

Question 10

A scientist is culturing bacteria using a medium with a known, exact chemical composition. This medium is best described as:

Accepted Answer

Chemically defined medium

Question 11

Which of the following best describes a missense mutation?

Accepted Answer

A base substitution that results in a different amino acid in the protein sequence.

Question 12

Which of the following is a function of the promoter region in transcription?

Accepted Answer

It is the binding site for RNA polymerase to initiate transcription.

Question 13

A patient is diagnosed with a disease that is not transmitted from person to person. This disease is classified as:

Accepted Answer

Noncommunicable

Question 14

Which of the following best describes the lag phase of bacterial growth?

Accepted Answer

Cells are metabolically active but not dividing.

Question 15

Which of the following is a direct method for measuring microbial growth?

Accepted Answer

Plate count

Question 16

A mutation that results in the insertion of a single nucleotide into a gene is most likely to cause:

Accepted Answer

Frameshift mutation

Question 17

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

Accepted Answer

It carries specific amino acids to the ribosome and matches them to the mRNA codons.

Question 18

Which of the following is a characteristic of an inducible operon?

Accepted Answer

It is usually off but can be turned on in the presence of a specific substrate.

Question 19

Which of the following best describes herd immunity?

Accepted Answer

When a high percentage of the population is immune, the spread of disease is limited.

Question 20

A researcher is studying a bacterial strain that can grow in the presence or absence of oxygen. This organism is best classified as:

Accepted Answer

Facultative anaerobe

Microbial Genetics, Growth, and Pathogenesis: Study Guide for Exam 2

Study Guide - Practice Questions