Question 1

Which of the following best describes the flow of genetic information in a bacterial cell?

Accepted Answer

$$DNA \rightarrow RNA \rightarrow Protein$$

Question 2

A mutation that results in the substitution of one base for another in DNA is called:

Accepted Answer

Base substitution (point mutation)

Question 3

Which of the following is a correct example of genotype affecting phenotype in bacteria?

Accepted Answer

A bacterium with the urease gene produces urease enzyme and turns urea broth purplish-pink

Question 4

What is the role of messenger RNA (mRNA) in gene expression?

Accepted Answer

It carries the genetic code from DNA to ribosomes for protein synthesis

Question 5

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

Accepted Answer

Transformation

Question 6

A frameshift mutation is most likely caused by:

Accepted Answer

Insertion or deletion of a base

Question 7

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids replicate autonomously and may carry antibiotic resistance genes

Question 8

During conjugation, what structure is used to transfer DNA between bacterial cells?

Accepted Answer

Sex pilus

Question 9

Which mechanism of horizontal gene transfer involves a viral intermediate?

Accepted Answer

Transduction

Question 10

What is the function of transposase in transposons?

Accepted Answer

It recognizes specific inverted repeat sequences and mediates movement of transposons

Question 11

Which of the following best describes vertical gene transmission?

Accepted Answer

Transfer of genes from parent to offspring during reproduction

Question 12

A bacterium that cannot synthesize a required nutrient due to a mutation is called:

Accepted Answer

Auxotroph

Question 13

Which of the following is a consequence of genetic recombination in bacteria?

Accepted Answer

Repair of defective genes or damaged DNA

Question 14

In Griffith’s experiment with Streptococcus pneumoniae, what was the 'transforming principle'?

Accepted Answer

DNA from dead virulent cells

Question 15

Which of the following is TRUE about the genetic code?

Accepted Answer

It is redundant, with multiple codons coding for the same amino acid

Question 16

What is the result of a nonsense mutation?

Accepted Answer

A premature stop codon, leading to truncated protein

Question 17

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

Accepted Answer

Binary fission

Question 18

If a bacterial cell receives a plasmid carrying an antibiotic resistance gene via conjugation, what is the most likely outcome?

Accepted Answer

The cell gains resistance to the specific antibiotic

Question 19

Which of the following best explains why mutations can be beneficial, neutral, or harmful?

Accepted Answer

The effect of a mutation depends on its impact on protein structure and function

Question 20

What is the main difference between generalized and specialized transduction?

Accepted Answer

Generalized transduction transfers any host gene, while specialized transduction transfers only specific genes

Microbial Genetics: Foundations, Gene Expression, and Mutation

Guida di studio - Domande di pratica