Question 1

Which of the following best describes the relationship between genotype and phenotype in a bacterial cell?

Accepted Answer

Genotype is the genetic makeup (DNA sequence), and phenotype is the observable traits resulting from gene expression.

Question 2

In prokaryotes, where is the genome primarily located?

Accepted Answer

In the nucleoid region

Question 3

Which of the following is a key difference between prokaryotic and eukaryotic chromosomes?

Accepted Answer

Prokaryotic chromosomes are usually circular and singular, while eukaryotic chromosomes are linear and multiple.

Question 4

What is the name of the extrachromosomal genetic element in bacteria that often carries antibiotic resistance genes?

Accepted Answer

Plasmid

Question 5

Which enzyme is responsible for synthesizing RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 6

Which of the following best explains why DNA replication is described as 'semiconservative'?

Accepted Answer

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

Question 7

Which type of chemical bond links deoxyribonucleotides together in a DNA strand?

Accepted Answer

Phosphodiester bond

Question 8

Refer to the following DNA sequence: 5'-CGTATGGGTCGA-3'. What would be the complementary DNA strand?

Accepted Answer

$$3'-GCATACCCAGCT-5'$$

Question 9

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

Accepted Answer

The lac operon is under both positive and negative control.

Question 10

What is the effect of a frameshift mutation within an open reading frame (ORF)?

Accepted Answer

It changes the reading frame, potentially altering every amino acid downstream.

Question 11

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

Accepted Answer

tRNA brings specific amino acids to the ribosome based on codon-anticodon pairing.

Question 12

Which of the following is a reason why tetracycline selectively kills bacteria but not eukaryotic cells?

Accepted Answer

Tetracycline inhibits bacterial ribosomes, which are structurally different from eukaryotic cytoplasmic ribosomes.

Question 13

Which process is unique to some viruses and not found in normal cellular information flow?

Accepted Answer

Reverse transcription

Question 14

What is the main function of the operator sequence in an operon?

Accepted Answer

It is the binding site for the repressor protein, regulating transcription.

Question 15

Which of the following best explains why coupled transcription and translation occur only in prokaryotes?

Accepted Answer

Prokaryotes do not have a nuclear envelope, allowing ribosomes to access mRNA as it is being transcribed.

Question 16

Which of the following is a consequence of a nucleotide insertion or deletion that is NOT a multiple of three within a coding region?

Accepted Answer

A frameshift mutation

Question 17

Which of the following is a difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose, while RNA contains ribose.

Question 18

Which of the following best describes the role of topoisomerases in DNA replication?

Accepted Answer

They relieve supercoiling tension ahead of the replication fork.

Question 19

Which of the following is TRUE regarding the Shine-Dalgarno sequence?

Accepted Answer

It is a ribosome binding site in prokaryotic mRNA.

Question 20

Which of the following best describes diauxic growth in bacteria?

Accepted Answer

Sequential use of two carbon sources, with a lag phase between them.

Microbiology Exam 2 Study Guide: Structure and Function of Genetic Material

Study Guide - Practice Questions