Question 1

Classification of organisms into three domains is based on
A) the number of cells in the organism.
B) cellular proteins.
C) the presence of a cell wall.
D) cellular organization.
E) nutritional requirements.

Accepted Answer

The classification of organisms into three domains (Bacteria, Archaea, and Eukarya) is based on differences in cellular organization, particularly the structure and composition of cell membranes and genetic material.

Question 2

Who is credited with first observing microorganisms?
A) Carolus Linnaeus
B) Anton van Leeuwenhoek
C) Robert Koch
D) Louis Pasteur
E) Robert Hooke

Accepted Answer

Anton van Leeuwenhoek is credited with first observing microorganisms using a microscope he designed.

Question 3

If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?
A) supplying the liquid with nutrients
B) starting with a liquid that contains microorganisms
C) adding antibiotics to the liquid
D) adding carbon dioxide to the liquid
E) using a sterile liquid and eliminating exposure to microorganisms

Accepted Answer

Using a sterile liquid and eliminating exposure to microorganisms is essential to disprove spontaneous generation, as it ensures that any microbial growth is not due to contamination from external sources.

Question 4

Archaea differ from bacteria in that archaea
A) use organic compounds for food.
B) are prokaryotic.
C) reproduce by binary fission.
D) lack nuclei.
E) have diverse cell wall compositions.

Accepted Answer

Archaea have diverse cell wall compositions, which differ from the peptidoglycan cell walls of bacteria.

Question 5

A prokaryotic cell may possess each of the following cellular components EXCEPT
A) ribosomes.
B) a cell membrane.
C) a nucleus.
D) a cell wall.
E) flagella.

Accepted Answer

Prokaryotic cells do not have a nucleus; their genetic material is not enclosed within a membrane-bound nucleus. Instead, it is located in a region called the nucleoid.

Question 6

The term used to describe a disease-causing microorganism is
A) pathogen.
B) bacterium.
C) infection.
D) microbe.
E) virus.

Accepted Answer

A pathogen is a microorganism that causes disease.

Question 7

Which of the following is NOT a domain in the three-domain system?
A) archaea
B) eukarya
C) bacteria
D) animalia

Accepted Answer

Animalia is not a domain in the three-domain system. The three domains are Archaea, Bacteria, and Eukarya.

Question 8

Common commercial benefits of microorganisms include synthesis of
A) riboflavin.
B) acetone.
C) insulin.
D) aspirin.
E) riboflavin, acetone and insulin.

Accepted Answer

Microorganisms can synthesize riboflavin, which is used as a vitamin supplement in animal feed and as a colorant in the food and beverage industry. Acetone, which can be produced by certain bacteria, has many industrial applications, including use as a solvent, a chemical intermediate, and as a component in nail polish remover. Insulin, a hormone used to regulate blood sugar levels in diabetic individuals, can be produced by genetically engineered bacteria. Therefore, microorganisms can benefit the commercial industry by synthesizing riboflavin, acetone, and insulin.

Question 9

Which of the following is NOT associated with viruses?
A) nucleic acid
B) organelles
C) envelope
D) chemical reactions
E) protein coat

Accepted Answer

Organelles are not associated with viruses. Viruses are not cells and do not have the complex internal structures that cells do, including organelles.

Question 10

Viruses are not considered living organisms because they
A) cannot reproduce by themselves.
B) can only be visualized using an electron microscope.
C) are structurally very simple.
D) are ubiquitous in nature.
E) are typically associated with disease.

Accepted Answer

Viruses are not considered living organisms because they cannot reproduce by themselves; they require a host cell to replicate.

Question 11

Microorganisms are involved in each of the following processes EXCEPT A) o₂ production. B) infection. C) smog production. D) decomposition of organic material. E) food production.

Accepted Answer

Microorganisms are not directly involved in smog production; smog is primarily caused by chemical reactions between pollutants in the atmosphere.

Question 12

Each of the following organisms would be considered a microbe EXCEPT
A) mushroom.
B) yeast.
C) virus.
D) protozoan.
E) bacterium.

Accepted Answer

Mushrooms are not microbes because they are not microscopic.

Question 13

Protozoan motility structures include
A) cilia.
B) flagella.
C) pseudopods.
D) cilia and pseudopods only.
E) cilia, flagella, and pseudopods.

Accepted Answer

Protozoa can have one or more of these structures for movement. Cilia, flagella, and pseudopods are all common motility structures found in protozoa. Therefore, the best choice is E, which includes all three structures.

Question 14

Figure 1.1  The bacterial shape of the cells in the scanning electron micrograph shown in Figure 1.1 would best be described as
A) spiral.
B) bacillus.
C) columnar.
D) ovoid.
E) coccus.

Accepted Answer

The answer of Figure 1.1  The bacterial shape of...

Question 15

In the name Staphylococcus aureus, aureus is the
A) genus.
B) domain name.
C) kingdom.
D) family name.
E) species.

Accepted Answer

In the binomial nomenclature system, the first part of the name (Staphylococcus) is the genus, and the second part (aureus) is the species.

Question 16

Who is credited with first observing cells?
A) Robert Koch
B) Robert Hooke
C) Anton van Leeuwenhoek
D) Louis Pasteur
E) Carolus Linnaeus

Accepted Answer

Robert Hooke was the first person to observe cells. He did this in 1665 using a microscope that he had built himself.

Question 17

Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Production of these products which are readily degraded and, thus, non-toxic typically utilizes
A) organic solvents.
B) alcohol.
C) organic acids.
D) enzymes.
E) soap.

Accepted Answer

Enzymes are biological catalysts that are biodegradable and non-toxic, making them ideal for environmentally friendly commercial applications.

Question 18

The formal system for classifying and naming organisms was developed by
A) Ignaz Semmelweis.
B) Carolus Linnaeus.
C) Louis Pasteur.
D) Robert Koch.
E) Aristotle.

Accepted Answer

Carolus Linnaeus developed the formal system of taxonomy, which is the classification and naming of organisms.

Question 19

The infectious agent that causes AIDS is a
A) virus.
B) protozoan.
C) bacterium.
D) mold.
E) yeast.

Accepted Answer

AIDS is caused by the Human Immunodeficiency Virus (HIV), which is a virus.

Question 20

Biogenesis refers to the
A) germ theory of disease.
B) spontaneous generation of organisms from nonliving matter.
C) development of aseptic technique.
D) development of life forms from preexisting life forms.

Accepted Answer

Biogenesis is the principle that living organisms are derived from other living organisms, not from nonliving matter.

Quiz 1: The Microbial World and You

Classification of organisms into three domains is based on

Who is credited with first observing microorganisms?

If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?

Archaea differ from bacteria in that archaea

A prokaryotic cell may possess each of the following cellular components EXCEPT

The term used to describe a disease-causing microorganism is

Which of the following is NOT a domain in the three-domain system?

Common commercial benefits of microorganisms include synthesis of

Which of the following is NOT associated with viruses?

Viruses are not considered living organisms because they

Microorganisms are involved in each of the following processes EXCEPT

Each of the following organisms would be considered a microbe EXCEPT

Protozoan motility structures include

Figure 1.1 The bacterial shape of the cells in the scanning electron micrograph shown in Figure 1.1 would best be described as

In the name Staphylococcus aureus, aureus is the

Who is credited with first observing cells?

Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Production of these products which are readily degraded and, thus, non-toxic typically utilizes

The formal system for classifying and naming organisms was developed by

The infectious agent that causes AIDS is a

Biogenesis refers to the