Question 1

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

Accepted Answer

Binary fission leads to exponential population growth under optimal conditions.

Question 2

A hospital patient develops a persistent infection associated with an indwelling catheter. Which microbial growth phenomenon is MOST likely responsible for the persistence of this infection?

Accepted Answer

Biofilm formation

Question 3

Which of the following equations correctly calculates the generation time of a bacterial culture?

Accepted Answer

$$Generation\ time\ (min) = \frac{Growth\ time\ (min)}{Number\ of\ generations}$$

Question 4

Which phase of the bacterial growth curve is characterized by a balance between cell division and cell death?

Accepted Answer

Stationary phase

Question 5

A researcher wants to keep a bacterial culture in the log phase for industrial enzyme production. Which device should be used?

Accepted Answer

Chemostat

Question 6

Which enzyme is responsible for converting superoxide ions ($$O_2$$^-$$) to hydrogen peroxide (H_2O_2$) in aerobic bacteria?

Accepted Answer

Superoxide dismutase

Question 7

A bacterium isolated from the Dead Sea is able to thrive in 30% NaCl. What is the correct term for this organism?

Accepted Answer

Halophile

Question 8

Which of the following best describes a chemoheterotroph?

Accepted Answer

Uses organic compounds for both energy and carbon

Question 9

Which type of media would you use to isolate and differentiate Staphylococcus aureus from other skin bacteria?

Accepted Answer

Mannitol salt agar

Question 10

Which physical method is MOST effective for sterilizing heat-sensitive medical equipment?

Accepted Answer

Ionizing radiation

Question 11

A microbiologist is using a spectrophotometer to estimate bacterial growth in a broth culture. What is being measured?

Accepted Answer

Turbidity (optical density)

Question 12

Which of the following statements about endospores is TRUE?

Accepted Answer

Endospores are highly resistant dormant structures formed by Bacillus and Clostridium.

Question 13

Which of the following is a correct pairing of a germicide and its highest level of activity?

Accepted Answer

Aldehydes – High-level

Question 14

A sample is streaked on blood agar and shows complete lysis of red blood cells. What type of hemolysis is this, and which pathogen is commonly identified this way?

Accepted Answer

Beta hemolysis; Streptococcus pyogenes

Question 15

Which of the following best describes the effect of high temperature on microbial enzymes?

Accepted Answer

Denatures cell proteins, leading to cell death

Question 16

Which of the following is a characteristic of fastidious organisms?

Accepted Answer

They require multiple growth factors supplied in the medium.

Question 17

Which of the following is the correct order of the four phases of bacterial growth in a closed batch culture?

Accepted Answer

Lag, Log, Stationary, Death

Question 18

A bacterium that grows best at pH 2 and is isolated from a volcanic vent is classified as a(n):

Accepted Answer

Acidophile

Question 19

Which of the following statements about selective media is TRUE?

Accepted Answer

Selective media contains ingredients that suppress the growth of some microbes while allowing others to grow.

Question 20

Which of the following control methods is MOST effective for eliminating prions from surgical instruments?

Accepted Answer

Combination of chemical treatments and increased temperature and pressure during autoclaving

Fundamentals of Microbial Growth: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards