Question 1

Which of the following statements correctly distinguishes prokaryotes from eukaryotes?

Accepted Answer

Prokaryotes lack a membrane-bound nucleus, while eukaryotes possess one.

Question 2

A scientist is studying a microorganism that thrives in extreme heat and has membrane lipids with ether linkages. Which domain does this organism most likely belong to?

Accepted Answer

Archaea

Question 3

Which of the following is NOT a feature shared by both prokaryotic and eukaryotic cells?

Accepted Answer

Cell wall (in all cells)

Question 4

Gram staining is used to differentiate bacteria based on their cell wall structure. What is the main difference between Gram-positive and Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane.

Question 5

During Gram staining, which step causes Gram-negative bacteria to lose the purple color and become colorless before counterstaining?

Accepted Answer

Decolorization with alcohol

Question 6

A bacterium is observed under a microscope and appears as a chain of rod-shaped cells. What is the correct classification for its shape and grouping?

Accepted Answer

Streptobacillus

Question 7

Which of the following best describes the genetic material in prokaryotic cells?

Accepted Answer

Circular DNA located in the nucleoid region

Question 8

Robert Koch developed a set of postulates to link specific microorganisms to diseases. Which of the following is NOT one of Koch’s postulates?

Accepted Answer

The microorganism must be able to survive outside the host for at least 24 hours.

Question 9

Which equation best represents the process of binary fission in bacteria, assuming each cell divides once per generation?

Accepted Answer

$N = N_0 	imes 2^n$

Question 10

A patient is diagnosed with a bacterial infection. The bacteria are found to be Gram-negative. Which of the following characteristics is most likely true for these bacteria?

Accepted Answer

They possess an outer membrane containing lipids and proteins.

Question 11

Which of the following scenarios best illustrates bacterial conjugation?

Accepted Answer

A bacterium transfers a plasmid to another bacterium through a pilus.

Question 12

Which of the following is a correct pairing of bacterial shape and its description?

Accepted Answer

Spirillum – spiral-shaped

Question 13

Which of the following statements about archaea is correct?

Accepted Answer

Archaea have membrane lipids that are ether-linked.

Question 14

Which of the following is a reason why some pathogenic bacteria cannot be cultured outside the body, making it difficult to fulfill Koch’s postulates?

Accepted Answer

They require specific host conditions that cannot be replicated in vitro.

Question 15

Which of the following cell structures is found in both prokaryotes and eukaryotes?

Accepted Answer

Ribosomes

Question 16

A microbiologist observes a cluster of spherical bacteria under the microscope. What is the correct term for this arrangement?

Accepted Answer

Staphylococcus

Question 17

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

Accepted Answer

They possess an outer membrane that acts as a barrier to many drugs.

Question 18

Which of the following is a metabolic process shared by both prokaryotes and eukaryotes?

Accepted Answer

DNA replication

Question 19

Which of the following best describes the function of the bacterial cell wall?

Accepted Answer

It provides structural support and protection.

Prokaryotes, Eukaryotes, and Bacterial Classification: Study Notes

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