Question 1

Which of the following best explains why small prokaryotic cells tend to grow faster than larger cells?

Accepted Answer

They have a higher surface area-to-volume ratio, allowing for more efficient nutrient exchange.

Question 2

A microbiologist wants to distinguish between Gram-positive and Gram-negative bacteria. Which staining method should they use, and what is the main structural difference revealed?

Accepted Answer

Gram stain; thickness of the peptidoglycan layer.

Question 3

Which of the following statements about the cytoplasmic membrane of Bacteria is CORRECT?

Accepted Answer

It acts as a permeability barrier, protein anchor, and is involved in energy conservation.

Question 4

Which microscopy technique would be most appropriate for visualizing the 3D structure of a biofilm without destroying the sample?

Accepted Answer

Confocal scanning laser microscopy (CSLM)

Question 5

A scientist observes a specimen that emits red light when illuminated with green light. Which microscopy technique is being used?

Accepted Answer

Fluorescence microscopy

Question 6

Which of the following is a unique feature of archaeal cytoplasmic membranes compared to bacterial membranes?

Accepted Answer

Ability to form lipid monolayers with ether linkages

Question 7

Which of the following best describes the function of peptidoglycan in bacterial cells?

Accepted Answer

It provides rigidity and structural strength to the cell wall.

Question 8

A bacterial cell is treated with lysozyme and penicillin. What is the most likely outcome?

Accepted Answer

The cell wall will be degraded, leading to cell lysis.

Question 9

Which of the following equations correctly represents the surface area-to-volume ratio ($$S/V) $$for a spherical cell of radius $$r$$?

Accepted Answer

$$S/V = \frac{4\pi r^2$}{\frac{4}{3}\pi r^3$}$$

Question 10

Which of the following statements about viruses is TRUE?

Accepted Answer

They rely entirely on the host cell's machinery for replication.

Question 11

A researcher wants to visualize the surface structure of a bacterial cell at high magnification. Which instrument and sample preparation method should they use?

Accepted Answer

Scanning electron microscope (SEM); coating with a thin film of heavy metal

Question 12

Which of the following best explains why phase-contrast microscopy is useful for observing live microbial cells?

Accepted Answer

It enhances contrast without the need for staining, allowing observation of living cells.

Question 13

Which of the following is a function of the bacterial cytoplasmic membrane?

Accepted Answer

Generation of proton motive force for energy conservation

Question 14

Which of the following best describes the difference between Gram-positive and Gram-negative bacterial cell walls?

Accepted Answer

Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane with LPS.

Question 15

Which of the following is a reason why bacterial morphology (shape) is NOT a reliable predictor of function?

Accepted Answer

Many bacteria with similar shapes have very different metabolic capabilities.

Question 16

Which of the following best describes the role of transport proteins in the cytoplasmic membrane?

Accepted Answer

They facilitate the accumulation of solutes against a concentration gradient.

Question 17

A sample contains a mixture of live and dead bacteria. Which microscopy technique would best allow you to distinguish between them using fluorescent dyes?

Accepted Answer

Fluorescence microscopy

Question 18

Which of the following statements about the Gram stain procedure is CORRECT?

Accepted Answer

Gram-positive cells appear purple after the procedure.

Question 19

Which of the following is a correct statement about the composition of peptidoglycan?

Accepted Answer

It is composed of N-acetylglucosamine, N-acetylmuramic acid, and amino acids.

Question 20

Which of the following best explains why archaeal membranes are more heat resistant than bacterial membranes?

Accepted Answer

They can form lipid monolayers with ether linkages.

Microbial Cell Structure and Function: Microscopy, Cell Morphology, and Cell Envelopes

Study Guide - Practice Questions

Study Guide - Flashcards