Question 1

Which of the following best describes the difference between catabolism and anabolism in microbial metabolism?

Accepted Answer

Catabolism involves the breakdown of molecules to release energy, while anabolism uses energy to build complex molecules.

Question 2

A researcher is studying a bacterial enzyme that requires a non-protein molecule to function. This molecule binds to the enzyme and is essential for its activity. What is this molecule called?

Accepted Answer

Cofactor

Question 3

Which of the following equations correctly represents the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

$$2~	ext{ATP}$$

Question 4

During aerobic respiration, which two types of phosphorylation reactions generate ATP?

Accepted Answer

Substrate-level phosphorylation and oxidative phosphorylation

Question 5

A bacterial culture is exposed to a temperature of $$80^\circ	ext{C}. $$Which type of microorganism is most likely to thrive under these conditions?

Accepted Answer

Thermophile

Question 6

Which of the following best explains why high concentrations of salt or sugar are effective preservatives for food?

Accepted Answer

They create a hypertonic environment, causing microbial cells to lose water and undergo plasmolysis.

Question 7

A scientist is using the streak plate method to isolate bacteria. What is the main purpose of this technique?

Accepted Answer

To obtain pure cultures by separating individual bacterial cells on an agar surface.

Question 8

Which of the following statements about the electron transport chain (ETC) in aerobic respiration is correct?

Accepted Answer

The ETC creates a proton gradient across the membrane, which drives ATP synthesis via chemiosmosis.

Question 9

Which of the following best describes the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments on the lagging strand by forming phosphodiester bonds.

Question 10

A mutation changes a codon from $$	ext{UAC} ($$tyrosine) to $$	ext{UAA} ($$stop codon). What type of mutation is this, and what is its likely effect?

Accepted Answer

Nonsense mutation; it results in premature termination of translation.

Question 11

Which of the following best describes the process of bacterial conjugation?

Accepted Answer

Direct transfer of DNA from one bacterium to another via a pilus, often involving an F plasmid.

Question 12

A researcher uses PCR (polymerase chain reaction) to amplify a DNA segment. Which of the following is a key advantage of PCR?

Accepted Answer

It can rapidly produce millions of copies of a specific DNA sequence from a small initial sample.

Question 13

Which of the following best explains why oxygen is toxic to some cells?

Accepted Answer

Oxygen can form reactive oxygen species (ROS) that damage cellular components.

Question 14

Which of the following is a correct description of a photoautotroph?

Accepted Answer

An organism that uses light as an energy source and $$	ext{CO}_2 as a $$carbon source.

Question 15

A bacterial population has a generation time of 30 minutes. If you start with 100 cells, how many cells will there be after 2 hours, assuming no cell death?

Accepted Answer

$$1600$$

Question 16

Which of the following best describes the role of restriction enzymes in recombinant DNA technology?

Accepted Answer

They cut DNA at specific sequences, allowing for the insertion of foreign DNA.

Question 17

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

Accepted Answer

Production of human insulin by genetically engineered bacteria.

Question 18

Which of the following best describes the CRISPR-Cas system's normal role in bacteria?

Accepted Answer

It provides adaptive immunity by recognizing and cutting foreign DNA from viruses.

Question 19

Which of the following best describes an amphibolic pathway?

Accepted Answer

A pathway that can function in both catabolism and anabolism.

Question 20

A scientist is analyzing a DNA fingerprint using the Southern blot technique. Which of the following best explains how this technique can distinguish between two DNA samples?

Accepted Answer

It separates DNA fragments by size and detects specific sequences, revealing unique banding patterns.

Comprehensive Study Guide for Microbiology: Metabolism, Nutrition, Genetics, and Biotechnology

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