Question 1

Which of the following best describes the difference between selective and differential media?

Accepted Answer

Selective media contain agents that inhibit the growth of certain microbes, while differential media contain indicators that reveal differences between organisms.

Question 2

A microbiologist wants to isolate a pure culture from a mixed sample. Which technique is most appropriate for this purpose?

Accepted Answer

Streak plate method

Question 3

Which of the following microorganisms would be classified as a thermophile?

Accepted Answer

A bacterium that grows optimally at $$55\ ^\circ \mathrm{C}$$

Question 4

Which statement correctly distinguishes phototrophs from chemotrophs?

Accepted Answer

Phototrophs use light as their energy source, while chemotrophs use chemical compounds.

Question 5

A fastidious microbe is best described as:

Accepted Answer

A microbe that requires specific nutrients and conditions for growth.

Question 6

During which phase of the bacterial growth curve are cells most susceptible to antibiotics targeting cell wall synthesis?

Accepted Answer

Log (exponential) phase

Question 7

A bacterial culture has a generation time of $$30$$ minutes. If it is grown for $$3$$ hours, how many generations have occurred?

Accepted Answer

$$6$$ generations

Question 8

Which of the following is a chemically defined medium?

Accepted Answer

A medium where all components and their concentrations are known

Question 9

Which method is considered an indirect way to estimate bacterial cell numbers?

Accepted Answer

Spectrophotometric measurement of turbidity

Question 10

Which term describes a chemical agent that kills bacteria?

Accepted Answer

Bactericidal

Question 11

Which physical method is most effective for sterilizing laboratory media?

Accepted Answer

Autoclaving at $$121\ ^\circ \mathrm{C}$$ and $$15$$ psi for $$15$$ minutes

Question 12

Which of the following statements about catabolism and anabolism is correct?

Accepted Answer

Catabolism releases energy, while anabolism consumes energy.

Question 13

Which factor does NOT directly influence enzyme activity?

Accepted Answer

Cell wall composition

Question 14

Which equation correctly represents the calculation of bacterial population after $$n$$ generations, starting from $$N_0$$ cells?

Accepted Answer

$$N = N_0$ 	imes 2^n$$

Question 15

Which metabolic pathway produces the most ATP per glucose molecule in prokaryotes?

Accepted Answer

Aerobic respiration

Question 16

Where does the Krebs cycle occur in prokaryotic cells?

Accepted Answer

Cytosol

Question 17

Why is pyruvate considered a central metabolite in cellular metabolism?

Accepted Answer

It is the end product of glycolysis and a substrate for the Krebs cycle and fermentation.

Question 18

Which component is NOT part of an ATP molecule?

Accepted Answer

Glucose

Question 19

Which biochemical test is used to detect the presence of the enzyme catalase in bacteria?

Accepted Answer

Catalase test

Question 20

A clinical sample is collected for bacterial identification. Which rapid analysis technique could be used to identify the specimen within hours?

Accepted Answer

PCR (Polymerase Chain Reaction)

Microbial Growth and Metabolism: Study Guide (Chapters 7-8)

Study Guide - Practice Questions

Study Guide - Flashcards