Question 1

Which experiment provided the strongest evidence against spontaneous generation and in favor of biogenesis?

Accepted Answer

Pasteur's swan-neck flask experiment

Question 2

Which of the following best describes the difference between Gram-positive and Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and one membrane

Question 3

A scientist observes that a bacterial cell is not killed by penicillin. Which of the following is the most likely explanation?

Accepted Answer

The cell is Gram-negative and has an outer membrane

Question 4

Which of the following statements about the Cell Theory is correct?

Accepted Answer

All living organisms are made of one or more cells, and all cells come from preexisting cells.

Question 5

Which of the following best explains why Gram staining is important in clinical microbiology?

Accepted Answer

It helps determine the appropriate antibiotic treatment.

Question 6

Which of the following is a correct sequence of steps in the Gram stain procedure?

Accepted Answer

Crystal violet, iodine, alcohol, safranin

Question 7

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

Accepted Answer

It protects the cell from phagocytosis and desiccation.

Question 8

A cell is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 9

Which of the following statements about passive and active transport is correct?

Accepted Answer

Active transport moves substances against their concentration gradient.

Question 10

Which scientist is correctly matched with their contribution to microbiology?

Accepted Answer

Louis Pasteur - disproved spontaneous generation

Question 11

Which of the following best describes the Endosymbiotic Theory?

Accepted Answer

Eukaryotic cells evolved from prokaryotic cells engulfing other prokaryotes, which became organelles.

Question 12

Which of the following is a function of the bacterial cell wall?

Accepted Answer

It provides shape, protection, and prevents osmotic lysis.

Question 13

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient with the help of membrane proteins

Question 14

Which of the following is NOT a correct pairing of a microorganism group and its cell wall composition?

Accepted Answer

Archaea - cellulose

Question 15

Which of the following best explains why antibiotic resistance is a significant healthcare problem?

Accepted Answer

Resistant bacteria survive antibiotic treatment, making infections harder to treat.

Question 16

Which of the following best describes the function of mitochondria in eukaryotic cells?

Accepted Answer

ATP production through cellular respiration

Question 17

Which of the following is a correct description of a mordant in staining procedures?

Accepted Answer

A chemical that increases the affinity of a dye for a specimen

Question 18

Which of the following best describes the difference between brightfield and darkfield microscopy?

Accepted Answer

Brightfield produces a bright background, darkfield produces a dark background

Question 19

Which of the following is a correct statement about the arrangement of bacterial flagella?

Accepted Answer

Monotrichous means a single flagellum at one end

Question 20

Which of the following best describes the structure of a phospholipid bilayer?

Accepted Answer

Hydrophilic heads face outward, hydrophobic tails face inward

Microbiology Study Guide: The Microbial World, Microscopy, and Cell Structure

Study Guide - Practice Questions