Question 1

Which of the following best describes a photoautotroph?

Accepted Answer

An organism that uses light for energy and inorganic carbon (CO$$_2) as $$its carbon source.

Question 2

A bacterium is found thriving in a hot spring at 70$$^	ext{o}C. $$Which term best describes its temperature preference?

Accepted Answer

Thermophile

Question 3

Which of the following statements about obligate anaerobes is correct?

Accepted Answer

They die in the presence of oxygen.

Question 4

During which stage of the microbial growth curve do cells prepare for division but do not increase in number?

Accepted Answer

Lag phase

Question 5

A culture of bacteria is placed in a medium with a pH of 3. Which group is most likely to thrive?

Accepted Answer

Acidophiles

Question 6

Which of the following equations best represents binary fission in bacteria, where $$N is $$the number of cells after $$n$$ generations and $$N_0 is $$the initial number of cells?

Accepted Answer

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

Question 7

A scientist observes a bacterial culture where the number of cells remains constant over time. Which stage of the growth curve is most likely being observed?

Accepted Answer

Stationary phase

Question 8

Which of the following organisms would be classified as a chemoautotroph?

Accepted Answer

An organism that uses chemicals for energy and CO$$_2$$ for carbon.

Question 9

A bacterium is able to grow in both the presence and absence of oxygen, but grows better with oxygen. Which term best describes this organism?

Accepted Answer

Facultative anaerobe

Question 10

Which of the following best describes the log phase of the microbial growth curve?

Accepted Answer

Cells are dividing at a constant, maximum rate.

Question 11

A researcher isolates a microorganism from a soda lake with a pH of 10. Which term best describes its pH preference?

Accepted Answer

Alkaliphile

Question 12

Which of the following is NOT a factor affecting microbial growth?

Accepted Answer

Replication via binary fission

Question 13

A hospital patient develops an infection from a bacterium that grows best at human body temperature (37$$^	ext{o}C). $$Which term best describes this organism?

Accepted Answer

Mesophile

Question 14

Which of the following scenarios best illustrates the concept of a facultative organism?

Accepted Answer

A bacterium that survives in both aerobic and anaerobic conditions.

Question 15

If a bacterial culture starts with 100 cells and undergoes 4 generations of binary fission, how many cells will be present? Use the formula $$N = N_0$ 	imes 2^n.$$

Accepted Answer

1600

Question 16

Which of the following is a characteristic of chemoheterotrophs?

Accepted Answer

They use organic compounds for both energy and carbon.

Question 17

A scientist is studying a microorganism that grows optimally at pH 7. Which term best describes this organism?

Accepted Answer

Neutrophile

Question 18

Which stage of the microbial growth curve is characterized by a decline in viable cell numbers?

Accepted Answer

Death phase

Question 19

A food company wants to prevent spoilage by psychrophiles. Which storage strategy would be most effective?

Accepted Answer

Store food at high temperatures (above 60$$^	ext{o}C).$$

Question 20

Which of the following best describes the relationship between environmental factors and microbial growth?

Accepted Answer

Microbial growth is influenced by temperature, pH, and oxygen availability.

Microbial Nutrition and Growth: Key Concepts and Growth Dynamics - CH 6

Study Guide - Practice Questions

Study Guide - Flashcards