Question 1

Which of the following best explains why transcription and translation can occur simultaneously in prokaryotes but not in eukaryotes?

Accepted Answer

Because prokaryotes lack a nuclear membrane, allowing ribosomes access to mRNA as it is transcribed.

Question 2

A sample of DNA contains 38% cytosine. What percentage of the nucleotides will be thymine?

Accepted Answer

12%

Question 3

Which enzyme is responsible for relieving tension ahead of the replication fork during DNA replication?

Accepted Answer

DNA gyrase

Question 4

A mutation changes a codon from $$	ext{UAA} to$$ $$	ext{UAC}. $$What type of mutation is this?

Accepted Answer

Missense mutation

Question 5

Which of the following statements about catabolite repression is FALSE?

Accepted Answer

When glucose is present, cAMP levels are high.

Question 6

Which of the following is NOT a feature of plasmids used for gene cloning?

Accepted Answer

They can remove introns from eukaryotic genes.

Question 7

A new antibiotic is discovered that targets the folic acid pathway. Which type of organism is most likely affected?

Accepted Answer

Bacteria

Question 8

Which of the following processes produces multiple copies of a specific region of DNA?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 9

Why are protozoan and fungal diseases generally more difficult to treat than bacterial diseases?

Accepted Answer

Their cells are structurally and functionally similar to human cells.

Question 10

Which of the following is NOT associated with DNA fingerprinting?

Accepted Answer

Nucleic acid sequencing

Question 11

Which of the following best describes the flow of genetic information in a cell?

Accepted Answer

DNA $$\rightarrow$$ RNA $$\rightarrow$$ protein

Question 12

Which of the following is the major effect of nonionizing UV radiation on a cell?

Accepted Answer

Bonding between adjacent nucleotides

Question 13

Which of the following enzymes is used to cut DNA at specific sites?

Accepted Answer

Restriction enzymes

Question 14

Which of the following is NOT a characteristic of E. coli that makes it a good host for producing recombinant proteins?

Accepted Answer

It can remove introns from eukaryotic genes.

Question 15

A base substitution mutation in a gene sometimes does not result in a different amino acid. Which factor accounts for this?

Accepted Answer

Some amino acids are produced from more than one codon.

Question 16

Which of the following is the correct sequence of bonds in DNA structure?

Accepted Answer

The sugar-phosphate backbone is held together by covalent bonds; the two strands are held together by hydrogen bonds.

Question 17

Which of the following is NOT a type of RNA?

Accepted Answer

cDNA

Question 18

Which of the following is the main reason why penicillin has a better therapeutic index than many other antimicrobial agents?

Accepted Answer

It targets peptidoglycan, which is unique to bacteria.

Question 19

Which of the following best describes conjugation in bacteria?

Accepted Answer

Transfer of genetic material involving a sex pilus

Question 20

A new antibiotic binds within the sequence $$	ext{AAUAUUAA}$$, thus interfering with which cellular process?

Accepted Answer

Translation

Microbiology Exam 2 & Practice Questions – Step-by-Step Study Guidance

Study Guide - Practice Questions