Question 1

Which of the following best describes why microorganisms are considered 'tiny titans of the Earth'?

Accepted Answer

They are the oldest form of life, inhabit every environment that supports life, and make up a major fraction of Earth's biomass.

Question 2

Which of the following is NOT a property shared by all microbial cells?

Accepted Answer

Cell wall

Question 3

A scientist is studying a microbe that has a single circular chromosome, no membrane-bound organelles, and sometimes contains plasmids. To which group does this organism most likely belong?

Accepted Answer

Bacteria

Question 4

Which of the following best explains why smaller prokaryotic cells can grow faster than larger eukaryotic cells?

Accepted Answer

They have a higher surface-to-volume ratio, allowing more efficient nutrient and waste exchange.

Question 5

Which of the following is a correct formula for the surface area to volume ratio ($$S/V) of a $$spherical cell with radius $$r$$?

Accepted Answer

$$S/V = 3/r$$

Question 6

Which of the following is NOT a domain of life?

Accepted Answer

Viruses

Question 7

A patient is diagnosed with cyclosporiasis after eating contaminated produce. Which of the following best describes Cyclospora?

Accepted Answer

A protozoan pathogen spread by ingestion of contaminated food or water

Question 8

Which of the following is a positive impact of microorganisms on food production?

Accepted Answer

Fermentation to produce yogurt and cheese

Question 9

Which of the following best describes the role of nitrogen-fixing bacteria in agriculture?

Accepted Answer

They convert atmospheric nitrogen ($$N_2) $$into ammonia ($$NH_3$$), which plants can use.

Question 10

Which of the following statements about viruses is TRUE?

Accepted Answer

Viruses are obligate parasites that replicate only within host cells.

Question 11

Which of the following is a reason why the leading causes of death in the United States shifted from infectious to noninfectious diseases between 1900 and 2016?

Accepted Answer

Increased use of antibiotics and vaccines

Question 12

Which of the following is an example of a biofilm and its significance?

Accepted Answer

A community of microbes growing on a medical implant, which can lead to persistent infections.

Question 13

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells contain membrane-bound organelles, while prokaryotic cells do not.

Question 14

Which of the following is a correct pairing of microbial morphology and description?

Accepted Answer

Spirillum: flexible spiral

Question 15

Which of the following is a correct sequence of events in the history of life on Earth?

Accepted Answer

First cells → anoxygenic phototrophs → oxygenic phototrophs → plants and animals

Question 16

Which of the following is a real-world application of biotechnology involving microorganisms?

Accepted Answer

Using genetically engineered bacteria to produce human insulin

Question 17

A researcher isolates a microbe from a hot spring with a temperature of 90°C and high acidity. Which group is this organism most likely to belong to?

Accepted Answer

Archaea

Question 18

Which of the following best describes the role of the gut microbiome in human health?

Accepted Answer

It digests complex carbohydrates and synthesizes vitamins.

Question 19

Which of the following is an example of a metabolic activity unique to some microbial cells but not all?

Accepted Answer

Motility via flagella

Question 20

Which of the following best explains why microbial ecology is important for understanding environmental changes?

Accepted Answer

Microbial metabolic activities can change habitats and affect other organisms.

Microbiology for Majors: Foundations and Applications

Study Guide - Practice Questions

Study Guide - Flashcards