Question 1

Which structural feature is unique to Gram-negative bacterial cell walls compared to Gram-positive cell walls?

Accepted Answer

Outer membrane containing lipopolysaccharide (LPS)

Question 2

Mycoplasma species are resistant to antibiotics targeting cell wall synthesis because:

Accepted Answer

They lack a cell wall entirely

Question 3

Which of the following best describes the function of a bacterial plasmid?

Accepted Answer

Carrying non-essential genes, often for antibiotic resistance

Question 4

During sporulation, which event occurs first in Bacillus species?

Accepted Answer

Formation of the forespore

Question 5

Which metabolic pathway is used by facultative anaerobes when oxygen is present?

Accepted Answer

Aerobic respiration

Question 6

In fermentation, the final electron acceptor is:

Accepted Answer

An organic molecule such as pyruvate

Question 7

Which microorganism would thrive in an environment with low oxygen concentration but not in its complete absence?

Accepted Answer

Microaerophile

Question 8

Which process involves the direct transfer of DNA from one bacterium to another via a pilus?

Accepted Answer

Conjugation

Question 9

Which type of genetic transfer in bacteria requires a bacteriophage?

Accepted Answer

Transduction

Question 10

Which of the following is a segmented, negative-sense RNA virus?

Accepted Answer

Influenza virus

Question 11

Plasmodium is considered a definitive host in malaria because:

Accepted Answer

It is the site of sexual reproduction

Question 12

Which DNA virus family replicates in the nucleus and is enveloped?

Accepted Answer

Herpesviridae

Question 13

Which of the following is a cytopathic effect (CPE) characterized by the fusion of multiple host cells into a single large cell?

Accepted Answer

Syncytia formation

Question 14

Which statement best describes the difference between exotoxins and endotoxins?

Accepted Answer

Exotoxins are secreted proteins, endotoxins are lipopolysaccharides released upon cell lysis

Question 15

Which bacterium is associated with the production of botulinum toxin?

Accepted Answer

Clostridium botulinum

Question 16

Which step in phagocytosis involves the fusion of the phagosome with lysosomes?

Accepted Answer

Formation of phagolysosome

Question 17

Which complement pathway is activated by antigen-antibody complexes?

Accepted Answer

Classical pathway

Question 18

Which function of complement directly leads to the destruction of pathogens by forming pores in their membranes?

Accepted Answer

Cytolysis

Question 19

Which cell type is primarily involved in the Th1 cell-mediated immune response?

Accepted Answer

T helper cells (CD4+)

Question 20

Which of the following equations represents the calculation of bacterial generation time ($g$) given the number of generations ($n$) and total time ($t$)?

Accepted Answer

$g = t / n$

Unit 4: Comprehensive Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards