Question 1

Which of the following best describes the flow of genetic information in most cells, as depicted in the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Question 2

Which enzyme is responsible for unwinding the DNA double helix during DNA replication?

Accepted Answer

Helicase

Question 3

In prokaryotic cells, where is the genetic material primarily located?

Accepted Answer

Nucleoid region

Question 4

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids are circular DNA molecules that can replicate independently of chromosomal DNA.

Question 5

Which of the following base pairs is found in RNA but NOT in DNA?

Accepted Answer

Adenine–Uracil

Question 6

During DNA replication, which enzyme replaces RNA primers with DNA nucleotides?

Accepted Answer

DNA polymerase I

Question 7

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

Accepted Answer

One strand runs 5' to 3', and the other runs 3' to 5'.

Question 8

A mutation changes a DNA triplet from TTT to ATT. What is the most likely effect on the resulting protein?

Accepted Answer

A nonsense mutation; a stop codon is introduced.

Question 9

Which process allows bacteria to acquire new genetic material from their environment without cell division?

Accepted Answer

Transformation

Question 10

Which of the following is a function of ribosomal RNA (rRNA)?

Accepted Answer

Combines with proteins to form ribosomes

Question 11

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation caused by insertion or deletion of nucleotides not divisible by three, altering all downstream codons

Question 12

Which enzyme is responsible for synthesizing the RNA primer during DNA replication?

Accepted Answer

Primase

Question 13

Which of the following is TRUE about eukaryotic genomes compared to prokaryotic genomes?

Accepted Answer

Eukaryotic genomes are organized with histones and contain multiple linear chromosomes.

Question 14

Which of the following is a correct description of conjugation in bacteria?

Accepted Answer

Transfer of a fertility plasmid through a pilus

Question 15

Which of the following is the correct formula for the directionality of DNA synthesis?

Accepted Answer

$$5' \rightarrow 3'$$

Question 16

Which of the following is a property of mRNA?

Accepted Answer

It carries the genetic code in codons to be translated into protein.

Question 17

Which of the following best explains why a single amino acid can be coded by multiple codons?

Accepted Answer

The genetic code is degenerate, providing redundancy that helps minimize the effects of mutations.

Question 18

Which of the following is a function of DNA ligase during DNA replication?

Accepted Answer

Seals nicks in the sugar-phosphate backbone by forming phosphodiester bonds

Question 19

Which of the following is a possible outcome of a nonsense mutation?

Accepted Answer

A truncated protein due to a premature stop codon

Question 20

Which of the following processes is unique to retroviruses and some specialized cells, and requires the enzyme reverse transcriptase?

Accepted Answer

Reverse transcription

Chapter 5: Microbial Genetics – Structure, Function, and Expression

Study Guide - Practice Questions