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

Question 1

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

Accepted Answer

Eukaryotic cells have a nucleus, whereas prokaryotic cells lack a true nucleus.

Question 2

A microbiologist observes a spherical bacterium arranged in clusters under the microscope. Which term best describes this arrangement?

Accepted Answer

Staphylococci

Question 3

Which component is found in the cell wall of Gram-positive bacteria but not in Gram-negative bacteria?

Accepted Answer

Teichoic acids

Question 4

A patient is diagnosed with a Mycoplasma infection. Which unique feature of Mycoplasma makes it resistant to antibiotics like penicillin?

Accepted Answer

Lack of a cell wall

Question 5

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

Accepted Answer

It protects bacteria from phagocytosis and desiccation.

Question 6

A Gram-negative bacterium is placed in a hypotonic solution. Which structure provides the primary protection against osmotic lysis?

Accepted Answer

Peptidoglycan layer

Question 7

Which of the following is a function of the bacterial flagellum?

Accepted Answer

Motility

Question 8

Which of the following best explains why Gram-negative bacteria are generally more resistant to antibiotics than Gram-positive bacteria?

Accepted Answer

They possess an outer membrane that restricts entry of many antibiotics.

Question 9

A scientist is using a compound microscope with a 10x ocular lens and a 40x objective lens. What is the total magnification?

Accepted Answer

$10 	imes 40 = 400$

Question 10

Which of the following statements about endospores is correct?

Accepted Answer

Endospores are highly resistant to heat, desiccation, and chemicals.

Question 11

Which of the following is NOT a function of the bacterial plasma membrane?

Accepted Answer

Protein synthesis

Question 12

A microbiologist stains a bacterial sample and observes a pink color under the microscope. What can be concluded about the cell wall structure?

Accepted Answer

The bacteria are Gram-negative with a thin peptidoglycan layer and an outer membrane.

Question 13

Which of the following best describes the function of bacterial fimbriae?

Accepted Answer

Attachment to surfaces

Question 14

Which of the following is a unique feature of eukaryotic cells compared to prokaryotic cells?

Accepted Answer

Presence of mitochondria

Question 15

A bacterial cell is observed to have a peritrichous arrangement of flagella. What does this mean?

Accepted Answer

Flagella are distributed over the entire surface of the cell.

Question 16

Which of the following statements about the human microbiome is correct?

Accepted Answer

The human microbiome can influence human health by aiding digestion and modulating the immune system.

Question 17

Which of the following best describes the function of the bacterial nucleoid?

Accepted Answer

It contains the bacterial chromosome (DNA).

Question 18

A patient is infected with a prion. Which of the following best describes a prion?

Accepted Answer

A misfolded protein that can cause disease

Question 19

Which of the following is the correct formula for calculating total magnification in a compound microscope?

Accepted Answer

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

Question 20

A bacterial cell is exposed to lysozyme, which breaks down peptidoglycan. What is the most likely outcome for the cell in a hypotonic environment?

Accepted Answer

The cell will undergo osmotic lysis.

Microbiology Study Notes: Prokaryotic and Eukaryotic Cell Structure & Light Microscopy

Study Guide - Practice Questions