Question 1

Which of the following best explains why prokaryotic cells are typically much smaller than eukaryotic cells?

Accepted Answer

Smaller cells have a higher surface area-to-volume ratio, allowing for more efficient nutrient uptake and waste removal.

Question 2

Which structure is responsible for the selective permeability of the bacterial cell membrane?

Accepted Answer

Phospholipid bilayer

Question 3

A bacterium is moved from a warm environment to a cold environment. How will it likely adapt its membrane lipid composition?

Accepted Answer

Increase the proportion of unsaturated fatty acids such as oleic acid

Question 4

Which of the following is a function of bacterial plasmids?

Accepted Answer

Confer selective advantages such as antibiotic resistance

Question 5

Which cytoskeletal protein is responsible for forming the Z ring during bacterial cell division?

Accepted Answer

FtsZ

Question 6

Which of the following statements about Gram-negative bacteria is TRUE?

Accepted Answer

They possess an outer membrane containing lipopolysaccharide (LPS).

Question 7

Why are peptidoglycan synthesis enzymes, such as transpeptidases, common targets for antibiotics?

Accepted Answer

Peptidoglycan is unique to bacteria, so targeting its synthesis does not harm human cells.

Question 8

Which of the following is a distinguishing feature of archaeal cell membranes compared to bacterial membranes?

Accepted Answer

Archaeal membranes contain ether-linked lipids, while bacterial membranes contain ester-linked lipids.

Question 9

Which component is found exclusively in Gram-positive bacterial cell walls?

Accepted Answer

Teichoic acids

Question 10

A patient develops septic shock after a Gram-negative bacterial infection. Which cell wall component is most likely responsible?

Accepted Answer

Lipopolysaccharide (LPS)

Question 11

Why are mycobacterial cell walls considered advantageous for the bacterium?

Accepted Answer

They are waxy and hydrophobic, providing resistance to desiccation and many antibiotics.

Question 12

Which of the following best describes the action of lysozyme on bacterial cell walls?

Accepted Answer

It cleaves the $$\beta(1-4)$$ glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid.

Question 13

Which of the following would NOT be a likely effect of a mutation that inactivates the FtsZ protein in a rod-shaped bacterium?

Accepted Answer

The bacterium would continue to divide normally.

Question 14

Which of the following is TRUE regarding the susceptibility of archaeal cell walls to lysozyme and penicillin?

Accepted Answer

Archaeal cell walls are generally resistant to both lysozyme and penicillin due to differences in sugar linkages and peptide cross-bridges.

Question 15

Which of the following best explains why Gram staining is a critical first step in identifying bacteria from an environmental sample?

Accepted Answer

It distinguishes bacteria based on cell wall structure, guiding further identification and treatment.

Question 16

Which of the following is a likely consequence if a bacterium loses its peptidoglycan layer?

Accepted Answer

It becomes susceptible to osmotic lysis.

Question 17

Which of the following is a correct pairing of bacterial morphology and example organism?

Accepted Answer

Spirochete – Borrelia burgdorferi

Question 18

Which of the following adaptations would you expect in a bacterium living in a high-temperature environment?

Accepted Answer

Increased proportion of saturated fatty acids in the membrane

Question 19

Which of the following statements about hopanoids is TRUE?

Accepted Answer

They are non-polar lipids in bacterial membranes that function similarly to cholesterol in eukaryotes.

Prokaryotic Structure: Cell Membranes & Walls (Bacteria and Archaea)

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