Question 1

Which of the following elements is NOT considered one of the six major elements (CHNOPS) required for microbial life?

Accepted Answer

Calcium

Question 2

A cyanobacterium like Anabaena is able to fix atmospheric nitrogen. What advantage does this provide in its ecological niche?

Accepted Answer

It can survive in environments lacking organic nitrogen sources.

Question 3

Which of the following best describes a photoautotroph?

Accepted Answer

Uses light for energy and CO$$_2$$ for carbon.

Question 4

In the microbial mat at Mushroom Spring, Yellowstone, the green layer at the top is dominated by filamentous cyanobacteria. What metabolic process do these organisms primarily perform?

Accepted Answer

Oxygenic photosynthesis

Question 5

Which of the following is a micronutrient (trace element) required by some microbes?

Accepted Answer

Zinc (Zn)

Question 6

A bacterium that uses H$$_2S as an $$electron donor and CO$$_2 as a $$carbon source is best classified as a:

Accepted Answer

Chemoautotroph

Question 7

Which of the following statements about microbial growth factors is TRUE?

Accepted Answer

Some microbes require vitamins from their environment because they cannot synthesize them.

Question 8

The symbiotic relationship between Riftia pachyptila (giant tube worm) and its bacterial symbiont is best described as:

Accepted Answer

Mutualism

Question 9

Which of the following equations correctly represents the process of oxygenic photosynthesis performed by cyanobacteria?

Accepted Answer

$$6CO_2 + 6H_2O + light \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 10

A microbe that cannot synthesize certain amino acids and must obtain them from the environment is said to require:

Accepted Answer

Growth factors

Question 11

Which of the following best explains why the cell wall acts as a barrier to organic debris, as shown in the provided diagram?

Accepted Answer

The cell wall prevents large, unprocessed organic molecules from entering the cell.

Question 12

Which of the following is a real-world example of a chemolithoautotroph?

Accepted Answer

A bacterium that oxidizes iron in acid mine drainage.

Question 13

Which of the following is NOT a function of the symbiont in the Riftia pachyptila holobiont system?

Accepted Answer

Immune system defense

Question 14

Which of the following best describes the role of magnesium (Mg) in microbial cells?

Accepted Answer

It is a macronutrient important for stabilizing ribosomes and nucleic acids.

Question 15

A bacterium that uses organic compounds as both its energy and carbon source is classified as a:

Accepted Answer

Chemoheterotroph

Question 16

Which of the following is a correct statement about the macromolecular composition of a typical microbial cell?

Accepted Answer

Proteins make up the largest percentage of cell dry weight.

Question 17

Which process allows microbes to obtain phosphorus for nucleic acid synthesis?

Accepted Answer

Assimilation of phosphate ions from the environment

Question 18

Which of the following best explains why vitamins are considered growth factors for some microbes?

Accepted Answer

They serve as coenzymes that some microbes cannot synthesize.

Question 19

A microbe living in a hydrothermal vent and using H$$_2S $$for energy and CO$$_2$$ for carbon is most likely a:

Accepted Answer

Chemoautotroph

Question 20

Which of the following is a plausible reason why trace elements like copper (Cu) are required by some microbes?

Accepted Answer

They serve as cofactors for specific enzymes.

Microbial Nutrition, Ecology, and Growth: Essential Elements and Metabolic Strategies

Study Guide - Practice Questions

Study Guide - Flashcards