Question 1

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

Accepted Answer

It is a semi-conservative process where each new DNA molecule consists of one old strand and one newly synthesized strand.

Question 2

During DNA replication, which enzyme is responsible for joining Okazaki fragments on the lagging strand?

Accepted Answer

DNA ligase

Question 3

In the context of gene expression, what is the main difference between prokaryotic and eukaryotic transcription and translation?

Accepted Answer

In prokaryotes, transcription and translation can occur simultaneously in the cytoplasm, while in eukaryotes, transcription occurs in the nucleus and translation in the cytoplasm.

Question 4

Which of the following correctly matches the type of mutation with its effect?

Accepted Answer

Frameshift mutation: results from the insertion or deletion of nucleotides, altering the reading frame

Question 5

A researcher exposes bacterial cells to ultraviolet (UV) light, which causes the formation of thymine dimers. Which repair mechanism is most likely to fix this damage?

Accepted Answer

Light repair (photoreactivation)

Question 6

Which of the following statements about the lac operon in E. coli is correct?

Accepted Answer

The lac operon is inducible and is turned on in the presence of lactose when glucose is absent.

Question 7

In Griffith's experiment, what was the key finding that demonstrated the process of transformation?

Accepted Answer

Living non-encapsulated bacteria mixed with heat-killed encapsulated bacteria killed the mouse, and encapsulated bacteria were recovered.

Question 8

Which of the following best describes the function of a plasmid in bacterial cells?

Accepted Answer

It is an extrachromosomal DNA element that can carry genes for antibiotic resistance or other advantageous traits.

Question 9

A bacterial cell with an integrated F plasmid in its chromosome is called:

Accepted Answer

Hfr cell (High frequency of recombination)

Question 10

Which of the following is an example of positive (direct) selection in microbiology?

Accepted Answer

Detecting antibiotic-resistant colonies that grow within a zone of inhibition around an antibiotic disk.

Question 11

In the Ames test, what does the appearance of many colonies on a plate lacking histidine indicate?

Accepted Answer

The histidine-dependent bacteria have undergone a reverse mutation to become histidine-independent.

Question 12

Which of the following best describes the process of conjugation in bacteria?

Accepted Answer

Direct transfer of plasmid DNA from a donor to a recipient cell via a sex pilus.

Question 13

A frameshift mutation is most likely to result from which of the following?

Accepted Answer

Insertion or deletion of one or two nucleotides

Question 14

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

Accepted Answer

The start codon for translation is always $$\mathrm{AUG}.$$

Question 15

Which of the following is a function of the p53 gene in human cells?

Accepted Answer

It acts as a surveillance gene, helping to monitor and repair DNA damage.

Question 16

Which of the following best explains why the mutation rate increases in the presence of mutagens?

Accepted Answer

Mutagens increase the frequency of errors in DNA, overwhelming the cell's repair mechanisms.

Question 17

Which of the following is NOT a characteristic of plasmids?

Accepted Answer

They are essential for the survival of the host cell.

Question 18

Which of the following is an example of horizontal gene transfer in bacteria?

Accepted Answer

Transfer of a plasmid from one bacterium to another via conjugation

Question 19

Transposons are best described as:

Accepted Answer

Segments of DNA that can move from one region of DNA to another

Question 20

A scientist is studying a bacterial operon that is normally 'on' but can be turned 'off' when a specific molecule binds to a repressor protein, activating it. Which type of operon is this?

Accepted Answer

Repressible operon

Chapter 8 Lecture Focused

Study Guide - Practice Questions

Study Guide - Flashcards