Question 1

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

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

Question 2

Which of the following statements about prokaryotic and eukaryotic genomes is correct?

Accepted Answer

Prokaryotic chromosomes are typically circular and found in the nucleoid.

Question 3

Which of the following is NOT a function of DNA methylation in bacteria?

Accepted Answer

Direct synthesis of ribosomal RNA

Question 4

During DNA replication, which enzyme is responsible for removing supercoils in the DNA?

Accepted Answer

Gyrase

Question 5

Which of the following best explains why DNA replication does not require ATP from the cell’s energy supply?

Accepted Answer

Triphosphate deoxyribonucleotides provide both the building blocks and the energy for DNA synthesis.

Question 6

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

Accepted Answer

Prokaryotic transcription occurs in the cytoplasm, while eukaryotic transcription occurs in the nucleus.

Question 7

Which of the following is true regarding the genetic code?

Accepted Answer

AUG serves as both a start codon and codes for methionine.

Question 8

A mutation that results in the substitution of one base pair for another, but does not change the amino acid sequence of the resulting protein, is called:

Accepted Answer

Silent mutation

Question 9

Which of the following best describes an inducible operon?

Accepted Answer

It must be activated by an inducer, such as the presence of a substrate.

Question 10

Which of the following is a real-world example of horizontal gene transfer by transformation?

Accepted Answer

A bacterium takes up free DNA from its environment and incorporates it into its genome.

Question 11

Which of the following statements about transposons is correct?

Accepted Answer

Transposons are segments of DNA that can move from one location to another within the same or different DNA molecule.

Question 12

Which of the following is a function of regulatory RNA molecules such as microRNAs (miRNAs)?

Accepted Answer

They bind to complementary mRNA and inhibit its translation.

Question 13

A hospital outbreak of Pseudomonas is traced to bacteria growing on soap. Which genetic mechanism most likely enabled these bacteria to survive in this unusual environment?

Accepted Answer

Altered gene expression regulated by operons

Question 14

Which of the following best explains why changes in RNA sequences due to poor transcription are less deleterious than DNA mutations?

Accepted Answer

RNA molecules are temporary and not inherited, while DNA mutations are permanent and passed to progeny.

Question 15

Which of the following is a characteristic of bacterial conjugation?

Accepted Answer

It involves the transfer of genetic material through direct cell-to-cell contact.

Question 16

Which of the following is a consequence of a frameshift mutation?

Accepted Answer

It changes the reading frame, potentially resulting in missense and nonsense mutations.

Question 17

Which of the following is a reason why the genetic ancestry of microbes is more difficult to ascertain than that of animals?

Accepted Answer

Horizontal gene transfer allows microbes to acquire genes from unrelated organisms.

Question 18

Which of the following is a difference between the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously in Okazaki fragments.

Question 19

Which of the following is true regarding the regulation of the trp operon in E. coli?

Accepted Answer

It is a repressible operon that is usually active but can be turned off when tryptophan is abundant.

Microbial Genetics: Structure, Replication, and Expression of Genomes

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