Question 1

Which of the following best describes the process of sterilization in microbiology?

Accepted Answer

The complete destruction or removal of all forms of microbial life, including endospores.

Question 2

Which of the following is a physical method used to control microbial growth?

Accepted Answer

Application of gamma radiation

Question 3

A food company wants to extend the shelf life of its products without using heat. Which method would be most appropriate?

Accepted Answer

Gamma radiation

Question 4

Which of the following best explains how osmotic pressure acts as a preservative?

Accepted Answer

It removes water from microbial cells, inhibiting their growth.

Question 5

Why is Taq polymerase used in the PCR procedure instead of DNA polymerase from E. coli?

Accepted Answer

Taq polymerase is stable at high temperatures required for PCR denaturation steps.

Question 6

If a researcher accidentally uses E. coli DNA polymerase instead of Taq polymerase in a PCR reaction, what is the most likely result?

Accepted Answer

DNA replication would not occur at all after the first denaturation step.

Question 7

Which of the following is a chemical method of controlling microbial growth?

Accepted Answer

Use of disinfectants such as bleach

Question 8

Which of the following statements about antibiotics is correct?

Accepted Answer

Antibiotics are substances produced by microorganisms that inhibit or kill other microorganisms.

Question 9

Which of the following best describes the mechanism of action of nucleoside analog drugs?

Accepted Answer

They mimic normal nucleotides and are incorporated into DNA, causing chain termination.

Question 10

Which of the following is essential for the polymerase chain reaction (PCR)?

Accepted Answer

DNA primers

Question 11

Which of the following best explains why sugar and salt act as preservatives?

Accepted Answer

They create a hypertonic environment that draws water out of microbial cells.

Question 12

Which of the following diseases has a vaccine available and has been used as a model for bioterrorism preparedness?

Accepted Answer

Smallpox

Question 13

Which of the following statements about vectors used in genetic engineering is FALSE?

Accepted Answer

Vectors contain low amounts of restriction sites for DNA insertion.

Question 14

Which of the following is the best definition of potable water?

Accepted Answer

Water that contains low amounts of microorganisms and is considered safe to drink.

Question 15

Which of the following is a real-world example of a non-perishable food due to microbial control methods?

Accepted Answer

Canned beans

Question 16

A hospital is choosing a method to sterilize heat-sensitive surgical instruments. Which method is most appropriate?

Accepted Answer

Gamma radiation

Question 17

Which of the following best describes the function of restriction endonucleases in molecular biology?

Accepted Answer

They cut DNA at specific sequences.

Question 18

Which of the following is a correct statement about the carbon cycle in microbiology?

Accepted Answer

Microorganisms decompose organic matter, releasing $\mathrm{CO_2}$ into the atmosphere.

Question 19

Which of the following is a reason why viral infections are often harder to treat than bacterial infections?

Accepted Answer

Viruses use host cell machinery, making selective targeting difficult.

Question 20

Which of the following best describes the process of horizontal gene transfer?

Accepted Answer

Transfer of genetic material between organisms that are not parent and offspring.

Microbiology Unit 4/Final Exam Study Guide

Study Guide - Practice Questions