Q: If a bacterial cell measures 150 nm in length, how many micrometers ($$\mum) is $$this, and could you see its detailed structure with a brightfield microscope (resolving power $$\approx 0.2\ \mum$$)?

$$150\ \text{nm} = 0.15\ \mu\text{m}$$; it is below the resolving power, so details cannot be seen.

Question 1

Which of the following statements best explains why viruses and prions are not considered living organisms?

Accepted Answer

They lack the ability to reproduce independently and do not possess cellular structures such as ribosomes or a plasma membrane.

Question 2

A microbiologist is examining a bacterium that is rod-shaped and found in chains. Which term best describes its shape and arrangement?

Accepted Answer

Bacillus; streptobacilli

Question 3

Which of the following is a characteristic shared by all living cells, including microbial cells?

Accepted Answer

They possess a plasma membrane that exhibits selective permeability.

Question 4

Which of the following best describes the difference between prokaryotic and eukaryotic ribosomes?

Accepted Answer

Prokaryotic ribosomes are 70S, while eukaryotic ribosomes are 80S, where S refers to Svedberg units.

Question 5

A patient is diagnosed with a bacterial infection caused by an obligate anaerobe. Which of the following best describes the growth requirements of this organism?

Accepted Answer

It cannot survive in the presence of oxygen.

Question 6

Which of the following statements about normal flora (normal microbiota) is correct?

Accepted Answer

Normal flora varies between individuals and is considered normal only in specific body sites.

Question 7

Which of the following best defines bioremediation?

Accepted Answer

The use of microorganisms to degrade environmental pollutants.

Question 8

A microbiologist wants to observe the surface details of a virus particle, which is smaller than the resolving power of a compound light microscope. Which microscope should they use?

Accepted Answer

Scanning electron microscope (SEM)

Question 9

If a bacterial cell measures 150 nm in length, how many micrometers ($$\mum) is $$this, and could you see its detailed structure with a brightfield microscope (resolving power $$\approx 0.2\ \mum$$)?

Accepted Answer

$$150\ 	ext{nm} = 0.15\ \mu	ext{m}$$; it is below the resolving power, so details cannot be seen.

Question 10

Which of the following best explains why Gram-negative bacteria stain pink after the Gram stain procedure?

Accepted Answer

They have a thin peptidoglycan layer and an outer membrane that allows the crystal violet-iodine complex to be washed out by alcohol.

Question 11

Which of the following statements about lipopolysaccharide (LPS) is correct?

Accepted Answer

LPS is found in the outer membrane of Gram-negative bacteria and contains Lipid A, which can act as an endotoxin.

Question 12

Which of the following is a correct statement about the acid-fast stain?

Accepted Answer

It is used to identify bacteria with mycolic acid in their cell walls, such as Mycobacterium and Nocardia.

Question 13

Which of the following is NOT a virulence factor discussed in Module 1?

Accepted Answer

Ribosomes

Question 14

Which of the following best describes the function of endospores in bacteria?

Accepted Answer

They allow bacteria to survive harsh environmental conditions by entering a dormant state.

Question 15

Which of the following statements about Koch’s postulates is correct?

Accepted Answer

They are a set of criteria used to establish a causative relationship between a microbe and a disease, but there are exceptions such as asymptomatic carriers.

Question 16

Which of the following best describes the contribution of Louis Pasteur to microbiology?

Accepted Answer

He disproved spontaneous generation and developed the process of pasteurization.

Question 17

Which of the following is a correct statement about the three domains of life?

Accepted Answer

The domain Archaea currently has no known pathogens.

Question 18

Which of the following best describes the function of gas vacuoles in microorganisms?

Accepted Answer

They provide buoyancy, allowing cells to adjust their position in the water column.

Question 19

Which of the following is a correct statement about the resolving power of a compound light microscope?

Accepted Answer

It is approximately $$0.2\ \mu	ext{m}$$, which limits its ability to resolve structures smaller than this.

Question 20

Which of the following best describes the arrangement of flagella known as 'peritrichous'?

Accepted Answer

Flagella are distributed over the entire surface of the cell.

Comprehensive Microbiology Study Guide: Chapters 1, 2, and 25

Study Guide - Practice Questions

Study Guide - Flashcards