$$\text{Viral titer} = \frac{\text{Number of plaques}}{\text{Dilution factor} \times \text{Volume plated}}$$

Question 1

Which structure is responsible for motility in most prokaryotes, and what is the primary mechanism by which it operates?

Accepted Answer

Flagella; by rotation powered by a proton gradient $$\Delta p$$

Question 2

Which bacterial genus is Gram-positive, forms endospores, and is known for causing botulism?

Accepted Answer

Clostridium

Question 3

What distinguishes Archaea from Bacteria in terms of cell wall composition?

Accepted Answer

Archaea lack peptidoglycan and often have pseudopeptidoglycan

Question 4

Which of the following is a disease caused by a protist and transmitted by a vector?

Accepted Answer

Plasmodium, transmitted by Anopheles mosquitoes

Question 5

Which of the following statements best describes the lysogenic cycle of a bacteriophage?

Accepted Answer

The viral genome integrates into the host DNA and remains dormant as a prophage

Question 6

Which equation best represents the exponential growth of bacteria under ideal conditions?

Accepted Answer

$$N = N_0$ e$$^{\mu t}$$

Question 7

Which of the following is NOT a characteristic of eukaryotic cells?

Accepted Answer

Peptidoglycan cell wall

Question 8

Which of the following fungi structures is responsible for nutrient absorption and forms the main body of the fungus?

Accepted Answer

Mycelium

Question 9

Which virus is classified as a retrovirus and is associated with the development of AIDS?

Accepted Answer

HIV

Question 10

What is the primary difference between Gram-positive and Gram-negative bacteria as revealed by Gram staining?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and retain crystal violet stain

Question 11

Which of the following is a latent virus that can cause cancer by activating oncogenes?

Accepted Answer

Human papillomavirus (HPV)

Question 12

Which equation describes the basic reproduction number ($$R_0) $$for an infectious disease?

Accepted Answer

$$R_0$$ = \frac{\beta}{\gamma}$$

Question 13

Which of the following is a benefit derived from Streptomyces bacteria?

Accepted Answer

Production of antibiotics

Question 14

Which protist is known for causing sleeping sickness and is transmitted by the tsetse fly?

Accepted Answer

Trypanosoma

Question 15

Which term describes a disease that spreads rapidly and affects a large number of people across several countries or continents?

Accepted Answer

Pandemic

Question 16

Which of the following is a unique feature of cyanobacteria?

Accepted Answer

Ability to fix atmospheric nitrogen

Question 17

Which equation best represents the calculation of viral titer using the plaque assay method?

Accepted Answer

$$	ext{Viral titer} = \frac{	ext{Number of plaques}}{	ext{Dilution factor} 	imes 	ext{Volume plated}}$$

Question 18

Which of the following is a characteristic of enveloped viruses?

Accepted Answer

They acquire their envelope from the host cell membrane during budding

Question 19

Which bacterial shape is described as spiral and is often associated with motility via axial filaments?

Accepted Answer

Spirochete

Question 20

Which of the following is a disease caused by a roundworm and transmitted through contaminated soil?

Accepted Answer

Ascariasis

Microbiology Chapters 11–13: Prokaryotes, Eukaryotes, and Viruses Study Guide

Study Guide - Practice Questions