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, but does not change the amino acid sequence of the protein, is called:

Accepted Answer

Silent 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

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 5

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

Accepted Answer

Transformation

Question 6

A frameshift mutation is most likely caused by:

Accepted Answer

Insertion or deletion of one or more bases

Question 7

Which of the following is a function of transposons in bacterial genetics?

Accepted Answer

They are mobile genetic elements that can move within and between DNA molecules.

Question 8

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 9

Which of the following best explains the redundancy of the genetic code?

Accepted Answer

There are more codons ($$64) $$than amino acids ($$20$$), so multiple codons can specify the same amino acid.

Question 10

A bacterial cell is found to be urease positive, producing a purplish-pink color in a urea test. Which of the following best explains this phenotype?

Accepted Answer

The cell's genotype includes a functional urease gene, which is transcribed and translated into the urease enzyme.

Question 11

Which of the following mechanisms of horizontal gene transfer requires a viral intermediate?

Accepted Answer

Transduction

Question 12

What is the role of RecA protein in bacterial recombination?

Accepted Answer

It mediates recombination between donor and recipient DNA at homologous regions.

Question 13

Which of the following best describes vertical gene transfer?

Accepted Answer

Transfer of DNA from parent to offspring during cell division.

Question 14

A missense mutation in a gene results in:

Accepted Answer

A single amino acid substitution in the protein sequence.

Question 15

Which of the following is TRUE regarding conjugative plasmids?

Accepted Answer

They possess genes for pilus formation and transfer.

Question 16

Which of the following is a possible consequence of a frameshift mutation?

Accepted Answer

All amino acids downstream of the mutation site are altered, possibly resulting in a premature stop codon.

Question 17

Which of the following best describes the role of the genetic code in translation?

Accepted Answer

It specifies the sequence of amino acids in a protein based on mRNA codons.

Question 18

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

Accepted Answer

Semiconservative replication

Question 19

A bacterial cell acquires a plasmid carrying an antibiotic resistance gene. This is an example of:

Accepted Answer

Horizontal gene transfer

Question 20

Which of the following statements about transposons is FALSE?

Accepted Answer

Transposons are always beneficial to the host cell.

Microbial Genetics: Foundations, Gene Expression, and Mutation

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