Question 1

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

Accepted Answer

Eukaryotic cells have a prominent nucleus, while prokaryotic cells lack a true nucleus.

Question 2

Which component is found in the plasma membrane of eukaryotic cells but NOT in prokaryotic cells?

Accepted Answer

Cholesterol

Question 3

A patient develops a persistent infection on a catheter despite repeated disinfection. Which microbial structure is most likely responsible for this phenomenon?

Accepted Answer

Biofilm

Question 4

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 containing porins and lipopolysaccharides.

Question 5

Which of the following transport mechanisms requires energy and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 6

A scientist observes a cell with a large periplasmic space, an outer membrane, and thin peptidoglycan. Which type of cell is being observed?

Accepted Answer

Gram-negative bacterial cell

Question 7

Which of the following is a function of membrane proteins in the plasma membrane?

Accepted Answer

Provide structural support

Question 8

Which equation best represents the movement of water across a semipermeable membrane from high to low concentration?

Accepted Answer

$$Osmosis: H_2O_{high} \rightarrow H_2O_{low}$$

Question 9

Which of the following best describes the role of enzymes in cellular reactions?

Accepted Answer

They act as biological catalysts to speed up reactions.

Question 10

A bacterial cell is placed in a solution with a higher concentration of solutes than inside the cell. What will most likely happen to the cell?

Accepted Answer

Water will move out of the cell by osmosis, causing it to shrink.

Question 11

Which process is illustrated by the equation below?

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$$

Accepted Answer

Aerobic cellular respiration

Question 12

Which of the following is TRUE about DNA replication in prokaryotes?

Accepted Answer

It is bidirectional and produces two identical DNA molecules.

Question 13

Which of the following best describes the function of the sodium-potassium pump?

Accepted Answer

It uses ATP to move sodium out of the cell and potassium into the cell.

Question 14

Which of the following is a key event during prophase of mitosis?

Accepted Answer

Chromosomes become visible and the nuclear membrane begins to dissolve.

Question 15

Which of the following mechanisms allows bacteria to acquire new genetic material from their environment?

Accepted Answer

Transformation

Question 16

A mutation that results in the insertion of a single nucleotide into a gene sequence is best described as:

Accepted Answer

Frameshift mutation

Question 17

Which of the following best explains why biofilms are a concern in healthcare settings?

Accepted Answer

They provide an environment for increased antibiotic resistance.

Question 18

Which of the following is a correct description of facilitated diffusion?

Accepted Answer

Movement of molecules from high to low concentration via a membrane protein, without energy input.

Question 19

Which of the following is a direct result of crossing over during meiosis?

Accepted Answer

Increased genetic diversity in gametes

Question 20

Which of the following best describes the lock-and-key model of enzyme activity?

Accepted Answer

Enzymes bind specific substrates at their active sites, facilitating a chemical reaction.

Cell Structure, Function, and Genetics in Microbiology

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