Question 1

Which of the following statements best distinguishes prokaryotic cells from eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a membrane-bound nucleus, while eukaryotic cells possess one.

Question 2

A bacterial cell is observed to lack a cell wall and is resistant to antibiotics that inhibit cell wall synthesis. Which genus does this bacterium most likely belong to?

Accepted Answer

Mycoplasma

Question 3

During the Gram stain procedure, what is the primary reason Gram-positive bacteria retain the crystal violet stain?

Accepted Answer

They have a thick layer of peptidoglycan in their cell wall.

Question 4

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

Accepted Answer

They help bacteria evade phagocytosis by host immune cells.

Question 5

A microbiologist is studying a bacterium that uses $\mathrm{NO_3^-}$ as its final electron acceptor during respiration. Which term best describes this metabolic process?

Accepted Answer

Anaerobic respiration

Question 6

Which of the following is a correct sequence of the phases in a typical bacterial growth curve?

Accepted Answer

Lag phase $\rightarrow$ Log (exponential) phase $\rightarrow$ Stationary phase $\rightarrow$ Death phase

Question 7

Which of the following statements about bacterial flagella is TRUE?

Accepted Answer

They are composed of the protein flagellin and are anchored in the cell membrane.

Question 8

A patient is infected with a bacterium that forms a biofilm on medical implants. Which structure is most directly involved in biofilm formation?

Accepted Answer

Capsule (glycocalyx)

Question 9

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

Accepted Answer

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

Question 10

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

Accepted Answer

It is the site of energy (ATP) production via the electron transport chain.

Question 11

Which of the following statements about endospores is correct?

Accepted Answer

Endospores are highly resistant structures formed by some bacteria to survive harsh conditions.

Question 12

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP acts as an intermediate molecule that couples catabolic and anabolic reactions.

Question 13

A bacterium is classified as a chemoautotroph. Which of the following best describes its nutritional strategy?

Accepted Answer

It uses inorganic chemicals as an energy source and $\mathrm{CO_2}$ as a carbon source.

Question 14

Which of the following is a correct description of competitive inhibition in enzyme activity?

Accepted Answer

A molecule similar in structure to the substrate binds to the active site, blocking substrate binding.

Question 15

During glycolysis, which of the following is the net gain of ATP molecules per molecule of glucose?

Accepted Answer

$2$

Question 16

Which of the following is NOT a product of fermentation?

Accepted Answer

Oxygen

Question 17

Which of the following statements about the electron transport chain (ETC) in prokaryotes is TRUE?

Accepted Answer

The ETC is located in the plasma membrane of prokaryotic cells.

Question 18

A bacterial cell is observed to have a thick, waxy cell wall that resists Gram staining and is acid-fast. Which genus does this bacterium most likely belong to?

Accepted Answer

Mycobacterium

Question 19

Which of the following best explains why enzymes are important in biological systems?

Accepted Answer

They lower the activation energy required for chemical reactions to occur.

Question 20

Which of the following statements about binary fission in bacteria is correct?

Accepted Answer

It results in two genetically identical daughter cells.

Fundamentals of Microbial Cell Structure, Function, and Metabolism

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