Question 1

Which of the following best describes the structure of the prokaryotic chromosome as seen in the first image?

Accepted Answer

A circular double-stranded DNA molecule that is supercoiled to fit inside the cell

Question 2

In the central dogma of molecular biology (see image 2), which enzyme is responsible for synthesizing RNA from a DNA template?

Accepted Answer

DNA-dependent RNA polymerase

Question 3

During bacterial cell division (see image 3), how is genetic information passed to daughter cells?

Accepted Answer

By vertical gene transfer

Question 4

Which of the following statements about DNA structure is correct (see image 6)?

Accepted Answer

The strands are antiparallel and held together by hydrogen bonds between complementary bases

Question 5

Which component is NOT part of a nucleotide (see image 7)?

Accepted Answer

A carboxyl group

Question 6

What is the main difference between deoxyribose and ribose sugars (see image 10)?

Accepted Answer

Ribose has an -OH group at the 2' carbon, deoxyribose has only an -H

Question 7

Which of the following best explains why DNA replication is considered semi-conservative (see image 15)?

Accepted Answer

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

Question 8

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

Accepted Answer

DNA ligase

Question 9

In prokaryotic transcription, what is the function of the promoter region?

Accepted Answer

It is the site where RNA polymerase binds to initiate transcription

Question 10

Which of the following codons is a start codon in translation, and what amino acid does it encode (see image 21)?

Accepted Answer

AUG, which encodes for methionine

Question 11

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

Accepted Answer

Nonsense mutation

Question 12

Which of the following best describes the effect of a frameshift mutation?

Accepted Answer

It shifts the reading frame, altering all downstream amino acids

Question 13

Which enzyme is responsible for removing RNA primers during DNA replication?

Accepted Answer

DNA polymerase

Question 14

Which of the following is a function of tRNA during translation?

Accepted Answer

It brings amino acids to the ribosome and matches them to the correct codon

Question 15

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

Accepted Answer

The lac operon is transcribed only when lactose is present and glucose is absent

Question 16

Which of the following is a real-world consequence of the high mutation rate of HIV reverse transcriptase?

Accepted Answer

HIV rapidly develops drug resistance, requiring combination therapy

Question 17

Which repair mechanism is used by humans to fix thymine dimers caused by UV light?

Accepted Answer

Nucleotide excision repair

Question 18

In the Ames test, what does an increased number of colonies on the experimental plate indicate?

Accepted Answer

The test chemical is mutagenic and possibly carcinogenic

Question 19

Which of the following best describes horizontal gene transfer?

Accepted Answer

Transfer of genes between cells of the same generation

Question 20

Which of the following is a mechanism by which Neisseria gonorrhoeae evades the immune system?

Accepted Answer

By antigenic variation through recombination and gene regulation

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

Study Guide - Practice Questions