Question 1

Which of the following best describes binary fission in bacteria?

Accepted Answer

It is an asexual process where a single cell divides into two genetically identical daughter cells.

Question 2

A hospital patient develops a persistent bloodstream infection after a catheter is inserted. Which microbial feature most likely contributes to the persistence of this infection?

Accepted Answer

Formation of biofilms on the catheter surface

Question 3

Which equation correctly calculates the number of cells $$N$$ after $$n$$ generations, starting from an initial population $$N_0$$?

Accepted Answer

$$N = N_0$ 	imes 2^n$$

Question 4

Which phase of the bacterial growth curve is characterized by rapid genome replication and exponential increase in cell number?

Accepted Answer

Log (exponential) phase

Question 5

A batch culture of E. coli is started with 100 cells. If the generation time is 20 minutes, how many cells will be present after 2 hours, assuming no cell death?

Accepted Answer

25,600

Question 6

Which of the following best explains why biofilms are difficult to treat in clinical settings?

Accepted Answer

Cells in biofilms communicate and collaborate, increasing resistance to antibiotics and host defenses.

Question 7

Which type of microbe would most likely thrive in a compost pile with temperatures around 70°C?

Accepted Answer

Thermophile

Question 8

A bacterium is found growing in Mono Lake, which has a pH of 10. What term best describes this organism?

Accepted Answer

Alkaliphile

Question 9

Which of the following statements about obligate anaerobes is correct?

Accepted Answer

They cannot survive in the presence of oxygen and lack enzymes to detoxify reactive oxygen species.

Question 10

Which enzyme converts hydrogen peroxide ($$H_2O_2) $$into water and oxygen, protecting cells from oxidative damage?

Accepted Answer

Catalase

Question 11

A microbe isolated from deep-sea hydrothermal vents can withstand high pressure and temperatures above 100°C. Which terms best describe this organism?

Accepted Answer

Barophile and extreme thermophile

Question 12

Which of the following is a correct description of the stationary phase in a bacterial growth curve?

Accepted Answer

Cell division rate equals cell death rate due to nutrient depletion and waste accumulation.

Question 13

Which of the following best describes the role of a chemostat in microbial culture?

Accepted Answer

It maintains microbial growth at a constant rate by continuously adding fresh media and removing waste.

Question 14

Which of the following microbes is most likely to be associated with foodborne illness due to its ability to grow at refrigerator temperatures?

Accepted Answer

Psychrotroph

Question 15

Which of the following is NOT a strategy used by acidophiles to survive in low pH environments?

Accepted Answer

Producing alkaline waste products to neutralize the environment

Question 16

A facultative anaerobe is placed in an environment with no oxygen. What metabolic process will it most likely use?

Accepted Answer

Fermentation

Question 17

Which of the following best describes the generation time for Mycobacterium tuberculosis under optimal conditions?

Accepted Answer

15–20 hours

Question 18

Which of the following is a correct statement about mesophiles?

Accepted Answer

They are associated with most human pathogens.

Question 19

Which of the following is a common misconception about microbial growth in nature compared to laboratory conditions?

Accepted Answer

Microbes in the laboratory always grow faster than in nature due to optimal conditions.

Question 20

Which of the following is the correct definition of a halophile?

Accepted Answer

A microbe that thrives in high salt concentrations

Chap 7A

Study Guide - Practice Questions

Study Guide - Flashcards