Question 1

Which of the following best explains why bacteria are useful in genetic studies?

Accepted Answer

Bacteria have super high mutation rates, making them ideal for studying genetic variation.

Question 2

A haploid organism is defined as one that:

Accepted Answer

Has only one copy of each gene per cell.

Question 3

Which statement about bacterial chromosomes is correct?

Accepted Answer

Bacterial chromosomes are usually a single, circular, double-stranded DNA molecule.

Question 4

What is the main difference between minimal and complete media for bacterial growth?

Accepted Answer

Minimal media contains only the nutrients required for growth, while complete media contains additional supplements.

Question 5

Which of the following best describes an auxotrophic mutant?

Accepted Answer

A bacterium that requires a specific nutrient supplement to grow due to a genetic mutation.

Question 6

In replica plating, what is the primary purpose of transferring colonies from a complete medium to a minimal medium?

Accepted Answer

To identify auxotrophic mutants that cannot grow on minimal medium.

Question 7

Which process involves the direct transfer of DNA from one bacterium to another via a pilus?

Accepted Answer

Conjugation

Question 8

During bacterial conjugation, what is the role of the F factor?

Accepted Answer

It enables the formation of a pilus for DNA transfer between cells.

Question 9

Which equation correctly represents the calculation of gene transfer time in Hfr mapping?

Accepted Answer

$$t = \frac{d}{v}$$

Question 10

If a bacterial strain is described as prototrophic, what does this mean?

Accepted Answer

It can synthesize all essential nutrients and grow on minimal medium.

Question 11

Which of the following is true about plasmids in bacteria?

Accepted Answer

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

Question 12

A scientist wants to map the order of genes on a bacterial chromosome using Hfr conjugation. Which observation would help determine the relative positions of genes?

Accepted Answer

The time at which each gene is transferred to the recipient cell.

Question 13

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

Accepted Answer

DNA is transferred between bacteria using a virus as a vector.

Question 14

In an experiment, a bacterial strain is unable to grow on minimal medium but grows on medium supplemented with methionine. What is the most likely genotype of this strain?

Accepted Answer

met-

Question 15

Which of the following is a key feature of high-frequency recombination (Hfr) strains?

Accepted Answer

They transfer chromosomal genes at a very high rate during conjugation.

Question 16

A partial diploid (merodiploid) in bacteria is best described as:

Accepted Answer

A cell with two copies of some genes due to the presence of an F' plasmid.

Question 17

Which of the following best explains why selective growth media are used in bacterial genetics experiments?

Accepted Answer

To permit only bacteria with specific genotypes to grow, enabling identification of mutants.

Question 18

Which process is most likely to result in the formation of a recombinant bacterial cell?

Accepted Answer

Conjugation with an Hfr donor

Question 19

A scientist observes that a bacterial strain can metabolize lactose only after glucose is depleted. This is an example of:

Accepted Answer

Catabolite repression

Question 20

Which of the following statements about gene mapping using Hfr strains is correct?

Accepted Answer

Genes that are transferred earlier during conjugation are closer to the origin of transfer.

Chapter 6 Genetic learning Book

Guida di studio - Domande di pratica

Study guide - Flashcard