Question 1

Which of the following best defines microbiology?

Accepted Answer

The study of organisms and acellular entities too small to be clearly seen by the unaided eye.

Question 2

Carl Woese's major contribution to microbiology was:

Accepted Answer

Establishing the 3-domain system based on ribosomal RNA gene sequences.

Question 3

Which of the following is NOT a characteristic of prokaryotic cells?

Accepted Answer

They have a membrane-enclosed nucleus.

Question 4

A newly discovered microbe is unicellular, lacks a membrane-bound nucleus, and has peptidoglycan in its cell wall. To which domain does it most likely belong?

Accepted Answer

Bacteria

Question 5

Which of the following is a real-world example of the importance of fungi to humans?

Accepted Answer

Production of antibiotics such as penicillin.

Question 6

Which of the following statements about the human microbiome is TRUE?

Accepted Answer

The collection of bacterial genes in and on your body exceeds your own genes by a factor of 100.

Question 7

Which of the following best describes the difference between Bacteria and Archaea?

Accepted Answer

Archaea lack peptidoglycan in their cell walls and have unique membrane lipids.

Question 8

Which of the following is an acellular microbe composed only of RNA?

Accepted Answer

Viroid

Question 9

A scientist observes a microbe that is filamentous, absorbs nutrients, and causes disease in plants. Which group does this organism most likely belong to?

Accepted Answer

Water molds (Oomycetes)

Question 10

Which of the following is a correct statement about the size of microorganisms?

Accepted Answer

Most bacteria are between $$1 \ \mu m$$ and $$10 \ \mu m in $$size.

Question 11

Which of the following is a major role of microorganisms in the environment?

Accepted Answer

Recycling essential elements such as carbon and nitrogen.

Question 12

Which of the following is a correct pairing of a microbe and its importance to humans?

Accepted Answer

Algae – source of photosynthetic oxygen and food in aquatic environments.

Question 13

Which of the following statements about the 3-domain system is correct?

Accepted Answer

It is based on comparison of ribosomal RNA gene sequences.

Question 14

A patient is diagnosed with a disease caused by a microbe that is unicellular, motile, and lacks a cell wall. Which group does this microbe most likely belong to?

Accepted Answer

Protozoa

Question 15

Which of the following is a unique feature of Archaea compared to Bacteria?

Accepted Answer

Some Archaea can produce methane (methanogenesis).

Question 16

Which of the following best explains why the human gut microbiota is important for brain development and behavior?

Accepted Answer

Gut microbes produce neuroactive compounds that can influence cognitive function and behavior.

Question 17

Which of the following is a correct description of a eukaryotic microbe?

Accepted Answer

A cell with a membrane-enclosed nucleus, such as a yeast.

Question 18

Which of the following is a correct statement about the diversity of microbes in the human gastrointestinal tract?

Accepted Answer

There are more than 200 species of microbes with a biomass of about $$1.5 \ kg.$$

Question 19

Which of the following is an example of a microbe that caused a significant historical event?

Accepted Answer

Phytophthora infestans, which caused the 1845 Irish potato famine.

Question 20

A researcher is studying an acellular entity composed of nucleic acid enclosed in a protein shell. Which type of microbe is being studied?

Accepted Answer

Virus

Introduction to Microbiology: Members of the Microbial World and Their Importance

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