Question 1

Which of the following best describes the process of semiconservative DNA replication in bacteria?

Accepted Answer

Each new DNA molecule consists of one parental strand and one newly synthesized strand.

Question 2

A scientist isolates a circular DNA molecule from a bacterium that is much smaller than the main chromosome and carries antibiotic resistance genes. What is this molecule most likely to be?

Accepted Answer

A plasmid

Question 3

During DNA replication, which enzyme is responsible for unwinding the double helix at the replication fork?

Accepted Answer

Helicase

Question 4

Which of the following best explains why a frameshift mutation can have a more severe effect on protein function than a point mutation?

Accepted Answer

Frameshift mutations change the reading frame, potentially altering every amino acid downstream.

Question 5

A bacterial cell is exposed to a bacteriophage that injects its DNA, which is then incorporated into the host genome. What is this process called?

Accepted Answer

Transduction

Question 6

Which of the following post-transcriptional modifications occurs in eukaryotic mRNA but not in prokaryotic mRNA?

Accepted Answer

Addition of a 5’ cap and a poly-A tail

Question 7

Given the DNA template strand: 3'-TACGGTACG-5', what is the corresponding mRNA sequence?

Accepted Answer

5'-AUGCCAUGC-3'

Question 8

Which of the following statements about the genetic code is correct?

Accepted Answer

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

Question 9

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

Accepted Answer

Nonsense mutation

Question 10

Which enzyme is responsible for joining Okazaki fragments on the lagging strand during DNA replication?

Accepted Answer

Ligase

Question 11

A bacterial cell with an F+ plasmid forms a pilus and transfers DNA to an F- cell. What is this process called?

Accepted Answer

Conjugation

Question 12

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

Accepted Answer

It brings specific amino acids to the ribosome based on its anticodon sequence.

Question 13

A patient is infected with a bacterial strain that has acquired resistance to multiple antibiotics. Which genetic process most likely contributed to this resistance?

Accepted Answer

Horizontal gene transfer via plasmids

Question 14

Which of the following is a purine base found in both DNA and RNA?

Accepted Answer

Adenine

Question 15

During transcription in bacteria, which enzyme synthesizes RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 16

A mutation in a gene does not change the amino acid sequence of the resulting protein. What type of mutation is this?

Accepted Answer

Silent mutation

Question 17

Which of the following best describes the antiparallel nature of DNA?

Accepted Answer

The two strands run in opposite 5' to 3' directions.

Question 18

Which of the following is NOT a mechanism by which bacteria can exchange genetic material?

Accepted Answer

Translation

Question 19

A scientist observes that after exposure to UV light, a bacterial gene has a single base pair deletion. What is the most likely consequence of this mutation?

Accepted Answer

A frameshift mutation, potentially resulting in a nonfunctional protein

Question 20

Which of the following correctly matches a DNA base with its complementary RNA base during transcription?

Accepted Answer

Adenine (A) pairs with Uracil (U)

Microbial Genetics: Key Concepts, Processes, and Vocabulary

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