Question 1

Which of the following best describes an auxotroph in a bacterial genetics experiment?

Accepted Answer

A bacterial strain that requires additional nutrients because it cannot synthesize a particular compound.

Question 2

In a genetic cross, what is the primary purpose of a backcross?

Accepted Answer

To determine the genotype of an individual by crossing it with a homozygous recessive parent.

Question 3

Which of the following statements about the F-factor in bacteria is correct?

Accepted Answer

The F-factor is a plasmid that enables bacteria to form a pilus and initiate conjugation.

Question 4

A researcher is studying linkage disequilibrium in a population. Which equation best represents the coefficient of linkage disequilibrium ($$D) $$between two loci?

Accepted Answer

$$D = p_{AB} - p_A p_B$$

Question 5

Which process involves the uptake of naked DNA by competent cells?

Accepted Answer

Transformation

Question 6

In bacterial conjugation, what is the function of the pilus?

Accepted Answer

It acts as a channel for DNA transfer between cells.

Question 7

A prototroph is best defined as:

Accepted Answer

A wild-type strain that can synthesize all essential nutrients and grow on minimal media.

Question 8

Which of the following is true about episomes?

Accepted Answer

Episomes are plasmids that can integrate into the bacterial chromosome.

Question 9

If two genes are in 'cis' configuration, which of the following is true?

Accepted Answer

Both mutant alleles are on the same chromosome.

Question 10

Which of the following best describes the role of tra genes in bacterial conjugation?

Accepted Answer

They encode proteins required for pilus formation and DNA transfer.

Question 11

A scientist uses sonication in a laboratory protocol. What is the primary purpose of sonication in genetics?

Accepted Answer

To fragment DNA by using high-frequency sound waves.

Question 12

Which of the following is a key difference between transduction and transformation in bacteria?

Accepted Answer

Transduction involves DNA transfer via a bacteriophage, while transformation involves uptake of naked DNA.

Question 13

In a genetic mapping experiment, the recombination fraction ($$r) $$between two loci is calculated as:

Accepted Answer

$$r = \frac{	ext{Number of recombinant offspring}}{	ext{Total number of offspring}}$$

Question 14

Which of the following best describes the term 'locus' in genetics?

Accepted Answer

A specific location on a chromosome where a gene or genetic marker is found.

Question 15

In a bacterial population, the presence of IS2 and IS3 elements can lead to which genetic phenomenon?

Accepted Answer

Insertion of transposable elements into the genome, causing mutations.

Question 16

Which of the following is true about minimal media used in bacterial genetics experiments?

Accepted Answer

Minimal media contains only the essential nutrients required for prototrophs to grow.

Question 17

A bacterial strain is described as 'nonrecombinant' after a genetic cross. What does this mean?

Accepted Answer

It retains the parental combination of alleles and has not undergone genetic recombination.

Question 18

Which of the following best describes the difference between coupling and repulsion in genetic linkage?

Accepted Answer

Coupling refers to both dominant alleles being on the same chromosome, while repulsion refers to dominant and recessive alleles being on opposite chromosomes.

Question 19

In a real-world scenario, a hospital isolates a strain of bacteria that is able to transfer antibiotic resistance genes to other strains via conjugation. Which genetic element is most likely responsible for this transfer?

Accepted Answer

Plasmid

Question 20

Which origin of replication is specifically associated with the transfer of plasmid DNA during conjugation?

Accepted Answer

oriT

Genetics of Bacteria: Key Terms and Concepts

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