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 a:

Accepted Answer

Point mutation

Question 3

Which of the following statements about plasmids is TRUE?

Accepted Answer

Plasmids are small, circular DNA molecules that replicate independently of the chromosome.

Question 4

In the process of transcription, which enzyme synthesizes RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 5

A bacterium is able to ferment lactose (Lac$$^+) $$due to the presence of a functional gene encoding a lactose-metabolizing enzyme. If a mutation occurs in this gene resulting in a nonfunctional enzyme, what is the most likely phenotype?

Accepted Answer

Lactose non-fermenting (Lac$$^-)$$

Question 6

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

Accepted Answer

Transfer of DNA via a sex pilus during conjugation

Question 7

A frameshift mutation is most likely caused by:

Accepted Answer

Insertion or deletion of a single base

Question 8

Which of the following best explains why the genetic code is described as 'redundant'?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 9

During conjugation between an Hfr cell and an F$$^-$$ cell, what is the most likely outcome for the recipient cell?

Accepted Answer

It remains F$$^-$$ but may acquire new chromosomal genes.

Question 10

Which of the following mechanisms involves the uptake of 'naked' DNA from the environment by a competent bacterial cell?

Accepted Answer

Transformation

Question 11

A transposon is best described as:

Accepted Answer

A mobile genetic element that can move within and between DNA molecules

Question 12

Which of the following is NOT a possible fate for external DNA acquired by a bacterial cell via horizontal gene transfer?

Accepted Answer

Immediate expression as a protein without transcription

Question 13

Which enzyme is responsible for mediating genetic recombination between donor and recipient DNA in bacteria?

Accepted Answer

RecA protein

Question 14

In Griffith’s experiment with Streptococcus pneumoniae, what was the key finding that demonstrated transformation?

Accepted Answer

Non-virulent bacteria became virulent after exposure to heat-killed virulent bacteria

Question 15

Which of the following best describes the role of the F (fertility) factor in bacterial conjugation?

Accepted Answer

It enables the formation of a sex pilus for DNA transfer.

Question 16

A mutation changes the DNA sequence from $$5'-AATGCCAGGGTAAA-3' to$$ $$5'-AATGCCAGGGTTAA-3'. $$What type of mutation is this?

Accepted Answer

Base substitution (point mutation)

Question 17

Which of the following is a consequence of a frameshift mutation in a coding region?

Accepted Answer

All amino acids downstream of the mutation may be altered

Question 18

Which process involves the transfer of bacterial DNA via a viral intermediate?

Accepted Answer

Transduction

Question 19

What is the function of transfer RNA (tRNA) during translation?

Accepted Answer

It brings amino acids to the ribosome according to the codon sequence.

Question 20

Which of the following best explains why recombination is important in bacterial populations?

Accepted Answer

It increases genetic diversity and can repair defective genes.

Microbial Genetics: Fundamentals of Gene Expression, Mutation, and Genetic Transfer

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