Question 1

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

Accepted Answer

Genotype is the set of genes an organism carries, while phenotype is the expression of those genes as observable traits.

Question 2

Which of the following statements about the structure of DNA and RNA is correct?

Accepted Answer

DNA is typically double-stranded, while RNA is usually single-stranded.

Question 3

According to the central dogma of molecular biology, what is the correct flow of genetic information in a cell?

Accepted Answer

$DNA \rightarrow RNA \rightarrow Protein$

Question 4

During which stage of protein synthesis does mRNA splicing occur in eukaryotic cells?

Accepted Answer

During transcription, before the mRNA leaves the nucleus.

Question 5

Which of the following is NOT a post-translational modification?

Accepted Answer

Splicing

Question 6

Which of the following best explains why the genetic code is considered redundant?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 7

Which of the following is an example of a spontaneous mutation?

Accepted Answer

A mutation resulting from a DNA polymerase error during replication.

Question 8

Which of the following best describes horizontal gene transfer in bacteria?

Accepted Answer

Transfer of genetic material between unrelated bacteria, often via plasmids.

Question 9

Which of the following mechanisms is NOT a method of horizontal gene transfer in bacteria?

Accepted Answer

Binary fission

Question 10

A scientist wants to demonstrate genetic transformation in E. coli. Which of the following steps is essential for this process?

Accepted Answer

Introducing purified plasmid DNA into competent E. coli cells.

Question 11

Which of the following best describes the function of the Ames test?

Accepted Answer

To assess the mutagenic potential of chemical compounds.

Question 12

Which of the following is a key difference between generalized and specialized transduction?

Accepted Answer

Generalized transduction can transfer any gene from the donor, while specialized transduction transfers only specific genes near the prophage site.

Question 13

Which of the following best describes a transposon and its role in genetic diversity?

Accepted Answer

A transposon is a segment of DNA that can move within the genome, creating mutations and increasing genetic diversity.

Question 14

Which of the following is an example of an induced mutation?

Accepted Answer

A mutation resulting from exposure to a chemical mutagen.

Question 15

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

Accepted Answer

Transfer of DNA from one bacterium to another via direct cell-to-cell contact.

Question 16

Which of the following is a function of mRNA in protein synthesis?

Accepted Answer

It acts as a template for the synthesis of proteins during translation.

Question 17

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that results in the substitution of one amino acid for another in the protein product.

Question 18

Which of the following is a mechanism by which bacteria can repair DNA damage?

Accepted Answer

Mismatch repair, which recognizes and corrects incorrectly paired bases.

Question 19

Which of the following best describes the role of regulatory proteins in gene expression?

Accepted Answer

They bind to DNA sequences to increase or decrease the transcription of specific genes.

Question 20

Which of the following is a real-world example of horizontal gene transfer contributing to antibiotic resistance?

Accepted Answer

A bacterium acquiring a resistance gene from a plasmid transferred by conjugation.

Genetics and Molecular Biology: Key Concepts and Mechanisms in Microbiology

Study Guide - Practice Questions