Question 1

Which of the following is the main feature that distinguishes prokaryotic cells from eukaryotic cells?

Accepted Answer

Presence of paired chromosomes in a nuclear membrane

Question 2

A bacterium is observed to have a single circular chromosome, no histones, and divides by binary fission. Which type of cell is this?

Accepted Answer

Prokaryotic cell

Question 3

Which of the following structures is found in eukaryotic cells but NOT in prokaryotic cells?

Accepted Answer

Organelles

Question 4

A microbiologist is studying a bacterium that is rod-shaped and forms chains. What is the correct term for this arrangement?

Accepted Answer

Streptobacilli

Question 5

Which of the following best describes a capsule in prokaryotic cells?

Accepted Answer

A neatly organized and firmly attached layer that prevents phagocytosis

Question 6

Which type of bacterial flagella arrangement consists of a tuft of flagella at one pole of the cell?

Accepted Answer

Lophotrichous

Question 7

What is the function of fimbriae in prokaryotic cells?

Accepted Answer

Attachment to surfaces

Question 8

Which component of the Gram-negative cell wall acts as an endotoxin and can trigger fever in humans?

Accepted Answer

Lipid A

Question 9

A patient is infected with Mycobacterium tuberculosis. Which cell wall component is responsible for its resistance to desiccation and many chemicals?

Accepted Answer

Mycolic acid

Question 10

Which enzyme hydrolyzes the bonds in peptidoglycan, leading to cell wall damage in bacteria?

Accepted Answer

Lysozyme

Question 11

A wall-less gram-positive cell is called a:

Accepted Answer

Protoplast

Question 12

Which of the following inclusions in prokaryotic cells is used for CO$$_2$$ fixation during photosynthesis?

Accepted Answer

Carboxysomes

Question 13

Endospores are produced by bacteria such as Bacillus and Clostridium when:

Accepted Answer

Nutrients are depleted

Question 14

Which of the following statements about plasmids is correct?

Accepted Answer

They carry non-crucial genes such as antibiotic resistance

Question 15

A scientist observes a bacterium moving toward a nutrient source. This movement is best described as:

Accepted Answer

Positive chemotaxis

Question 16

Which of the following is a correct formula for the average size range of bacterial cells?

Accepted Answer

$$0.2 \leq d \leq 2.0\ \mu m$$\ (diameter),\ 2 \leq l \leq 8\ \mu m$\ (length)

Question 17

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

Accepted Answer

Their outer membrane protects against many antibiotics

Question 18

Which of the following is a function of magnetosomes in prokaryotic cells?

Accepted Answer

Destroying H$$_2O$_2$$

Question 19

A bacterium is observed to have a cell wall composed of pseudomurein. Which domain does it most likely belong to?

Accepted Answer

Archaea

Question 20

Which process describes the return of an endospore to its vegetative state?

Accepted Answer

Germination

Ch. 2

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