Question 1

Which of the following best describes a micronutrient in microbial nutrition?

Accepted Answer

A substance present in much smaller amounts, involved in enzyme function and maintenance of protein structure.

Question 2

A bacterium that obtains its carbon from organic molecules and relies on other life forms is classified as:

Accepted Answer

Heterotroph

Question 3

Which type of symbiotic relationship is characterized by one organism benefiting while the other is neither harmed nor helped?

Accepted Answer

Commensalism

Question 4

Biofilms are an example of which type of microbial association?

Accepted Answer

Synergism

Question 5

Facilitated diffusion across a cell membrane is characterized by which two features?

Accepted Answer

Saturation and competition

Question 6

A solution with a higher concentration of solutes outside the cell than inside is called:

Accepted Answer

Hypertonic

Question 7

Which of the following statements about microbial growth and temperature is correct?

Accepted Answer

Microbes are unable to control their internal temperature and must adapt to their habitat's temperature variation.

Question 8

A microbe that grows best at a higher CO$$_2$$ tension than is normally present in the atmosphere is called:

Accepted Answer

Capnophile

Question 9

Which enzyme is produced by aerobes to protect themselves from reactive oxygen species (ROS)?

Accepted Answer

Superoxide dismutase

Question 10

Halophiles are microorganisms that:

Accepted Answer

Prefer high concentrations of salt for growth.

Question 11

During which phase of the bacterial growth curve are cells most vulnerable to antimicrobial agents?

Accepted Answer

Exponential (log) phase

Question 12

A continuous culture system that maintains a steady stream of nutrients and stabilizes cell number is called:

Accepted Answer

Chemostat

Question 13

Which method allows for the differentiation between live and dead cells in a microbial population?

Accepted Answer

Flow cytometer

Question 14

A facultative anaerobe is best described as:

Accepted Answer

A microbe that grows better in the presence of O$$_2$$ but does not require it.

Question 15

If a bacterial population doubles every 30 minutes, how many cells will there be after 3 hours if you start with 100 cells? Use the formula $$N = N_0$ 	imes 2^n$$, where $$n is $$the number of generations.

Accepted Answer

6400 cells

Question 16

Which of the following is NOT a stage in the normal bacterial growth curve?

Accepted Answer

Sporulation phase

Question 17

A tube of clear nutrient solution becomes cloudy as microbes grow in it. This method of estimating population size is called:

Accepted Answer

Turbidometry

Question 18

Which of the following best explains why obligate halophiles lyse in hypotonic environments?

Accepted Answer

Their cell walls and membranes are adapted to high salt concentrations and cannot withstand low osmotic pressure.

Question 19

Which of the following is a real-world application of PCR in microbiology?

Accepted Answer

Quantifying bacteria in environmental and tissue samples without culturing them.

Question 20

A microbe that grows optimally at pH 2 is classified as:

Accepted Answer

Obligate acidophile

Question 21

Which of the following statements about binary fission is correct?

Accepted Answer

Binary fission involves chromosome duplication and division into two daughter cells.

Microbial Nutrition and Growth: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard