Question 1

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

Accepted Answer

It allows bacteria to move toward or away from stimuli, a process known as chemotaxis.

Question 2

A scientist observes a prokaryotic cell with a thick peptidoglycan layer and no outer membrane. Which Gram stain result and cell type is most likely?

Accepted Answer

Gram-positive; bacillus

Question 3

Which of the following best explains why viruses are not classified as living organisms?

Accepted Answer

They cannot reproduce independently and lack cellular structure.

Question 4

During glycolysis, glucose is converted into which molecule, and what is the net gain of ATP per glucose molecule?

Accepted Answer

Pyruvate; $2$ ATP

Question 5

Which of the following statements about the structure of the bacterial cell envelope is correct?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and teichoic acids.

Question 6

A patient is diagnosed with a bacterial infection. The bacteria are rod-shaped and form chains. Which term best describes their morphology?

Accepted Answer

Streptobacillus

Question 7

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

Accepted Answer

Protects against phagocytosis by host immune cells

Question 8

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

Accepted Answer

Eukaryotic cells have a nucleus; prokaryotic cells lack a nucleus.

Question 9

Which of the following is the correct order of taxonomic classification from broadest to most specific?

Accepted Answer

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 10

A microbiologist is studying a bacterium that can survive in the absence of oxygen by using nitrate as a terminal electron acceptor. Which process is this bacterium using?

Accepted Answer

Anaerobic respiration

Question 11

Which of the following best describes the function of fimbriae in bacteria?

Accepted Answer

Attachment to surfaces and other cells

Question 12

Which of the following statements about binary fission is correct?

Accepted Answer

It results in the formation of genetically identical daughter cells.

Question 13

A Gram-negative bacterium is exposed to penicillin. Which structural feature makes it less susceptible to this antibiotic compared to Gram-positive bacteria?

Accepted Answer

Presence of an outer membrane containing lipopolysaccharide (LPS)

Question 14

Which of the following best explains why mitochondria are considered to have evolved from prokaryotic cells?

Accepted Answer

They contain circular DNA and reproduce by binary fission.

Question 15

Which of the following is a distinguishing feature of Archaea compared to Bacteria?

Accepted Answer

Ether-linked membrane lipids

Question 16

A patient presents with symptoms of a viral infection. Which of the following structures would you expect to find in the causative agent?

Accepted Answer

Capsid composed of protein

Question 17

Which of the following best describes the function of the nucleoid in prokaryotic cells?

Accepted Answer

It contains the cell's genetic material in a single, circular DNA molecule.

Question 18

Which of the following is a correct statement about the process of endospore formation?

Accepted Answer

It allows bacteria to survive extreme conditions such as heat and desiccation.

Question 19

Which of the following best explains the selective permeability of the plasma membrane?

Accepted Answer

It regulates the movement of substances in and out of the cell based on size, charge, and solubility.

Question 20

A microbiologist is using a bright field microscope to observe a bacterial sample. Which of the following best describes the principle behind this technique?

Accepted Answer

It relies on light passing through the specimen, with denser areas appearing darker.

Fundamental Concepts in Microbiology: Cell Structure, Classification, and Key Terms

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