$\text{Total Magnification} = \text{Ocular Lens Magnification} \times \text{Objective Lens Magnification}$

Question 1

Which of the following statements best explains why electron microscopes have a much higher resolution than light microscopes?

Accepted Answer

Electron microscopes use electrons, which have a shorter wavelength than visible light, allowing for a resolution up to 0.2 nm.

Question 2

A Gram-positive bacterium is observed under a microscope. Which cell wall feature distinguishes it from a Gram-negative bacterium?

Accepted Answer

A thick layer of peptidoglycan containing teichoic acids.

Question 3

Which formula correctly calculates the total magnification of a brightfield microscope?

Accepted Answer

$	ext{Total Magnification} = 	ext{Ocular Lens Magnification} 	imes 	ext{Objective Lens Magnification}$

Question 4

A bacterial cell is placed in a hypertonic solution. What is the most likely outcome?

Accepted Answer

Water will flow out of the cell, causing it to shrink.

Question 5

Which of the following best describes the function of the capsule/slime layer in bacteria?

Accepted Answer

It prevents the cell from drying out and allows it to adhere to surfaces, aiding in biofilm formation.

Question 6

Which metabolic strategy is used by bacteria when the final electron acceptor is an inorganic molecule other than oxygen, such as Fe, H2, or S?

Accepted Answer

Anaerobic respiration

Question 7

During glycolysis, how many net ATP molecules are produced per glucose molecule?

Accepted Answer

$2$

Question 8

Which of the following is a key advantage of a high surface area to volume ratio in microbial cells?

Accepted Answer

It allows for faster exchange of nutrients and waste, promoting rapid growth.

Question 9

Which statement about passive transport across the cell membrane is correct?

Accepted Answer

It does not require energy and moves substances down their concentration gradient.

Question 10

A scientist observes a bacterium with a spiral shape under the microscope. Which term best describes its morphology?

Accepted Answer

Spirillum

Question 11

Which of the following is NOT a component of the Gram-negative lipopolysaccharide (LPS)?

Accepted Answer

Teichoic acid

Question 12

Which process in bacteria involves the uptake of nutrients by engulfing them into membrane-bound vesicles?

Accepted Answer

Endocytosis

Question 13

Which equation correctly represents the surface area (S) of a sphere, which is important for understanding microbial cell exchange?

Accepted Answer

$S = 4 \pi r^2$

Question 14

Which of the following statements about mitochondria and chloroplasts supports the endosymbiotic theory?

Accepted Answer

They have their own DNA and divide by binary fission.

Question 15

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

Accepted Answer

It provides structural support and protects against osmotic lysis.

Question 16

Which electron carrier is reduced during glycolysis and the citric acid cycle?

Accepted Answer

NAD+

Question 17

A bacterial cell is placed in an isotonic solution. What will happen to the cell?

Accepted Answer

There will be no net movement of water; the cell remains unchanged.

Question 18

Which of the following best describes the role of ATP in active transport across the cell membrane?

Accepted Answer

ATP provides energy to move molecules against their concentration gradient.

Question 19

Which of the following is a correct summary of ATP production in eukaryotic cells during aerobic respiration?

Accepted Answer

$38$ ATP per glucose molecule

Question 20

Which of the following statements about biofilms is correct?

Accepted Answer

Biofilms are communities of microorganisms that adhere to surfaces and are protected from chemicals and antibiotics.

Foundations of Microbiology: Cell Structure, Function, and Bioenergetics

Study Guide - Practice Questions