Question 1

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

Accepted Answer

It protects bacteria from phagocytosis and desiccation.

Question 2

A Gram-negative bacterium is treated with lysozyme. What is the most likely outcome?

Accepted Answer

The outer membrane remains, forming a spheroplast.

Question 3

Which of the following equations correctly represents the calculation of generation time ($$g) in $$bacterial growth?

Accepted Answer

$$g = \frac{t}{n}$$

Question 4

During which phase of the bacterial growth curve are cells most susceptible to antibiotics targeting cell wall synthesis?

Accepted Answer

Log (exponential) phase

Question 5

A culture starts with 1,000 cells and after 3 hours contains 8,000 cells. Assuming exponential growth, what is the generation time ($$g$$)? Use $$n = \log_2$ \left( \frac{N_t}{N_0$} \right)$$ and $$g = \frac{t}{n}.$$

Accepted Answer

$$g = 1$$ hour

Question 6

Which structure is unique to Gram-negative bacteria and contributes to their resistance to certain antibiotics?

Accepted Answer

Outer membrane containing lipopolysaccharide (LPS)

Question 7

Which of the following best explains why endospores are difficult to destroy?

Accepted Answer

They possess a thick cortex and spore coat that protect against heat and chemicals.

Question 8

A patient presents with a wound infection. The Gram stain shows purple, spherical cells in clusters. Which organism is most likely responsible?

Accepted Answer

Staphylococcus aureus

Question 9

Which of the following statements about bacterial flagella is correct?

Accepted Answer

They are anchored in the cell membrane by the basal body.

Question 10

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

Accepted Answer

Attachment to surfaces

Question 11

A microbiologist wants to sterilize a solution that is heat-sensitive. Which method is most appropriate?

Accepted Answer

Filtration through a $$0.22\ \mu m$$ membrane

Question 12

Which of the following is a correct statement about the structure of peptidoglycan?

Accepted Answer

It is composed of repeating units of N-acetylglucosamine and N-acetylmuramic acid linked by peptide bridges.

Question 13

Which of the following best explains the difference between a protoplast and a spheroplast?

Accepted Answer

A spheroplast is a Gram-negative cell with its outer membrane partially intact after cell wall removal.

Question 14

Which of the following is the correct order of the Gram stain procedure?

Accepted Answer

Crystal violet, iodine, alcohol, safranin

Question 15

Which of the following best describes the function of teichoic acids in Gram-positive bacteria?

Accepted Answer

They help anchor the cell wall to the cell membrane and may play a role in ion transport.

Question 16

A bacterial culture is in stationary phase. Which of the following best explains what is happening at the cellular level?

Accepted Answer

The rate of cell division equals the rate of cell death.

Question 17

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

Accepted Answer

Selective permeability and energy generation

Question 18

Which of the following best explains why Mycobacterium species are acid-fast?

Accepted Answer

They have mycolic acids in their cell wall.

Question 19

A patient is diagnosed with a Clostridium infection. Which property of Clostridium makes it particularly difficult to eradicate from hospital environments?

Accepted Answer

Ability to form endospores

Question 20

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

Accepted Answer

Protein synthesis

Microbial Growth, Nutrition, and Environmental Factors: Study Notes

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