Question 1

Which statement best describes the Central Dogma of Molecular Biology?

Accepted Answer

It describes the flow of genetic information from DNA to RNA to protein.

Question 2

How many chromosomes are typically found in a bacterial cell such as Escherichia coli?

Accepted Answer

1

Question 3

During DNA replication, what is the primary function of DNA polymerase III?

Accepted Answer

It synthesizes new DNA strands by adding nucleotides to the 3' end.

Question 4

What are Okazaki fragments and why are they necessary during DNA replication?

Accepted Answer

Short DNA fragments synthesized on the lagging strand due to the antiparallel nature of DNA.

Question 5

Which enzyme is responsible for joining Okazaki fragments together during DNA replication?

Accepted Answer

DNA ligase

Question 6

In bacterial transcription, what is the role of the promoter?

Accepted Answer

It is the site where RNA polymerase binds to initiate transcription.

Question 7

Which of the following best describes the difference between induction and repression in operon regulation?

Accepted Answer

Induction increases gene expression in response to a substrate; repression decreases gene expression in response to an end product.

Question 8

What is the function of the lac operon in E. coli?

Accepted Answer

It controls the breakdown of lactose when it is present.

Question 9

Which of the following is a point mutation?

Accepted Answer

A single nucleotide change in the DNA sequence.

Question 10

A frameshift mutation is most likely caused by:

Accepted Answer

Insertion or deletion of one or more nucleotides not in multiples of three.

Question 11

Which type of mutation is most commonly induced by UV light?

Accepted Answer

Thymine dimer formation

Question 12

What is the difference between an auxotroph and a prototroph?

Accepted Answer

An auxotroph requires a specific nutrient for growth that a prototroph does not.

Question 13

Which process involves the uptake of naked DNA from the environment by a bacterial cell?

Accepted Answer

Transformation

Question 14

In the process of translation, what is the role of the ribosome?

Accepted Answer

It assembles amino acids into a polypeptide chain based on the mRNA sequence.

Question 15

Given the mRNA codon $$\mathrm{AUG}$$, what amino acid does it code for and why is it important?

Accepted Answer

It codes for methionine, which serves as the initiator for translation.

Question 16

Which enzyme is primarily responsible for synthesizing RNA during transcription?

Accepted Answer

RNA polymerase

Question 17

What is the main difference between bacterial and eukaryotic transcription?

Accepted Answer

Bacterial transcription uses a single RNA polymerase, while eukaryotes use multiple types.

Question 18

Which of the following best describes the Ames test?

Accepted Answer

A test to detect mutagenic potential of chemical compounds using auxotrophic bacteria.

Question 19

Which process involves the transfer of genetic material between bacteria via a pilus?

Accepted Answer

Conjugation

Question 20

If a base analog is incorporated into DNA during replication, what is the most likely result?

Accepted Answer

An increased rate of point mutations due to mispairing.

Core Concepts in Microbial Genetics and Molecular Biology

Study Guide - Practice Questions