Question 1

Which of the following best describes the process of replica plating in identifying bacterial mutants?

Accepted Answer

It involves transferring colonies from a master plate to secondary plates with different selective media to identify mutants.

Question 2

Which test is commonly used to determine if a chemical is a mutagen by measuring its ability to induce mutations in bacteria?

Accepted Answer

Ames test

Question 3

What is the main difference between conjugation and transformation in bacteria?

Accepted Answer

Conjugation requires direct cell-to-cell contact, while transformation involves uptake of free DNA from the environment.

Question 4

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

Accepted Answer

Transduction by bacteriophages

Question 5

Griffith's experiment with Streptococcus pneumoniae demonstrated which genetic phenomenon?

Accepted Answer

Transformation

Question 6

Which equation best represents the frequency of mutations per cell division if $$N is $$the number of mutants and $$T is $$the total number of cells?

Accepted Answer

$$f = \frac{N}{T}$$

Question 7

A bacterial cell acquires a gene for antibiotic resistance from a virus. This is an example of:

Accepted Answer

Transduction

Question 8

Which of the following best describes a frameshift mutation?

Accepted Answer

An insertion or deletion of nucleotides that changes the reading frame of the gene

Question 9

Which process is used to repair thymine dimers caused by UV light in bacterial DNA?

Accepted Answer

Photoreactivation

Question 10

Which of the following statements about plasmids is correct?

Accepted Answer

Plasmids are extrachromosomal DNA molecules that can carry antibiotic resistance genes.

Question 11

Which of the following is NOT a possible outcome of a point mutation in a gene?

Accepted Answer

A change in the reading frame of the gene

Question 12

Which of the following best describes recombinant DNA technology?

Accepted Answer

The artificial joining of DNA from two different sources to create new genetic combinations

Question 13

Which enzyme is commonly used to cut DNA at specific sequences during genetic engineering?

Accepted Answer

Restriction endonuclease

Question 14

A scientist wants to clone a gene into a plasmid vector. Which enzyme is needed to join the gene to the plasmid?

Accepted Answer

DNA ligase

Question 15

Which of the following is a real-world application of recombinant DNA technology?

Accepted Answer

Production of human insulin by genetically engineered bacteria

Question 16

Which of the following best describes the role of the lac operon in E. coli?

Accepted Answer

It regulates the metabolism of lactose in response to environmental availability.

Question 17

Which of the following is a potential risk associated with the use of genetically modified organisms (GMOs)?

Accepted Answer

Unintended spread of modified genes to wild populations

Question 18

Which of the following is a common method for introducing recombinant DNA into bacterial cells?

Accepted Answer

Transformation

Question 19

Which of the following best explains why the Ames test uses a strain of Salmonella that cannot synthesize histidine?

Accepted Answer

To detect mutations that restore the ability to synthesize histidine, indicating mutagenicity

Question 20

Which of the following is a key ethical concern in the use of recombinant DNA technology in medicine?

Accepted Answer

Potential for unintended effects on human health and the environment

Microbiology Study Guide: Genetics, Mutations, and DNA Technology

Study Guide - Practice Questions