Chapter 21 Viruses, Bacteria, Archaea, and Protists: The Diversity of Life 1
1) Which organisms accomplish most of the work of converting atmospheric nitrogen into a form usable to green plants?
A) bacteria and archaea
B) viruses
C) protists
D) fungi
Answer: A
Topic: Section 21.1
Skill: Knowledge/Comprehension
2) The main decomposers on Earth are the:
A) viruses and protists.
B) plants and animals.
C) bacteria and fungi.
D) plants and fungi.
Answer: C
Topic: Section 21.1
Skill: Knowledge/Comprehension
3) The material in the core of HIV (AIDS virus) is:
A) protein.
B) xarbohydrate.
C) DNA.
D) RNA.
Answer: D
Topic: Section 21.2
Skill: Knowledge/Comprehension
4) The viral capsid is:
A) a fatty membrane surrounding the virus.
B) the genetic material at the core.
C) a protein coat around the genetic material.
D) the viral offspring that rupture the cell and escape.
Answer: C
Topic: Section 21.2
Skill: Knowledge/Comprehension
5) Which of the following is the best description of a virus?
A) A virus is the smallest living thing.
B) A virus is a life-form that can reproduce inside cells or independently.
C) A virus is a tiny spore-producing cell.
D) A virus is a noncellular, replicating entity.
Answer: D
Topic: Section 21.2
Skill: Knowledge/Comprehension
6) The process by which viruses can exchange genetic sequences to come up with a "new" virus such as H1N1 is:
A) recombination.
B) reassortment.
C) independent assortment.
D) conjugation.
Answer: B
Topic: Section 21.2
Skill: Knowledge/Comprehension
7) The life cycle of viruses involves:
A) production of new virus particles on the outside of a cell.
B) reproducing on the surface of a cell.
C) filling the host cell with viral particles.
D) attaching viral DNA to the surface of a cell.
Answer: C
Topic: Section 21.2
Skill: Knowledge/Comprehension
8) Which phrase most accurately describes the genome of most viruses?
A) surprisingly complex, with tens of thousands of genes
B) surprisingly complex, with around 1 million genes
C) the same as most bacteria, with hundreds of genes
D) relatively simple, with around a dozen genes or fewer
Answer: D
Topic: Section 21.2
Skill: Application/Analysis
9) The human immunodeficiency virus targets:
A) lymph nodes.
B) all white blood cells.
C) helper T cells.
D) bone marrow cells.
Answer: C
Topic: Section 21.2
Skill: Knowledge/Comprehension
10) A major difference between bacteria and eukaryotes is that bacteria have:
A) a rod-shaped nucleus.
B) no membrane-bound organelles.
C) faster mitosis as their method of sexual reproduction.
D) no ribosomes.
Answer: B
Topic: Section 21.3
Skill: Application/Analysis
11) Which of the following would support the statement that bacteria represent the most fundamentally diverse group on Earth?
A) Bacteria exist in varieties with and without cell walls.
B) Bacteria accomplish all characteristics of life as small, single cells.
C) Bacteria are metabolically diverse regarding oxygen and food requirements.
D) Bacteria come in several different shapes.
Answer: C
Topic: Section 21.3
Skill: Application/Analysis
12) Which statement about the relationship between bacteria and the human body is most accurate?
A) Although many tissues are kept bacteria-free, around 100 trillion bacteria live on or in us.
B) About one-tenth of our body weights are due to bacteria
C) Bacteria are found in the mouth, stomach, and intestines in about equal amounts.
D) Most bacteria are transient; that is, they come for brief periods and then are gone.
Answer: A
Topic: Section 21.4
Skill: Application/Analysis
13) Which of the following would support the hypothesis that bacteria have mutually beneficial relationships with us?
A) Bacteria derive benefit from waste materials in our intestines.
B) Mice that were made "germ free" did not absorb and metabolize nutrients as well.
C) Bacteria can metabolize food using alternate pathways.
D) Most intestinal bacteria cannot live outside the body.
Answer: B
Topic: Section 21.4
Skill: Application/Analysis
14) Bacteria that benefit from living in or on us while we are unaffected by the relationship are termed:
A) commensal.
B) pathogenic.
C) mutualistic.
D) probiotic.
Answer: A
Topic: Section 21.5
Skill: Knowledge/Comprehension
15) A bacterium that is pathogenic:
A) is flexible regarding use of metabolic pathways.
B) has genes similar to viruses.
C) is a disease-causing organism.
D) benefits from living inside humans and produces nutrients for us.
Answer: C
Topic: Section 21.5
Skill: Knowledge/Comprehension
16) The botulism bacterium can kill a person by:
A) killing muscle cells.
B) secreting a toxin that paralyzes muscles.
C) causing brain hemorrhages.
D) producing lethally high fevers.
Answer: B
Topic: Section 21.5
Skill: Knowledge/Comprehension
17) If antibiotics seem effective against a human illness, then this illness is probably caused by a/an:
A) protist.
B) autoimmune disease.
C) virus.
D) bacterium.
Answer: D
Topic: Section 21.5
Skill: Application/Analysis
18) In general, most antibiotics work by:
A) exploiting differences between human and bacterial cells.
B) preventing bacteria from entering human cells.
C) preventing viruses from entering human cells.
D) boosting the human immune system.
Answer: A
Topic: Section 21.5
Skill: Knowledge/Comprehension
19) The antibiotic penicillin inhibits the ability of bacteria to:
A) make cell walls.
B) synthesize protein.
C) copy DNA.
D) undergo respiration.
Answer: A
Topic: Section 21.5
Skill: Knowledge/Comprehension
20) Which of the following is true of Domain Archaea compared to other groups?
A) They are the only anaerobes on Earth.
B) Their cell wall and membrane biochemistry is unique.
C) Most of their genes are similar to those found in bacteria.
D) None of their genes work like those found in eukaryotes.
Answer: B
Topic: Section 21.6
Skill: Application/Analysis
Refer to the scenario below, and then answer the following question(s).
As part of your field biology independent study, you visit a small lake with an extremely high salt concentration. Searching with nets and other sampling devices, you find no fish, plants, algae, or any visible signs of life in the lake. Still, you decide to take a few samples of the water back to the lab. You find the sample teeming with very small cells, hundreds of times smaller than a typical human cell. These cells have cell walls, which you analyze chemically and find they are not made of peptidoglycan or cellulose.
21) Based upon the environment in which you found these life-forms, how would you categorize them?
A) thermophiles
B) halophiles
C) anaerobes
D) methanogens
Answer: B
Topic: Section 21.6
Skill: Synthesis/Evaluation
22) Based upon the chemical experiments you performed, how would you classify these life-forms?
A) protists
B) fungi
C) bacteria
D) archaea
Answer: D
Topic: Section 21.6
Skill: Synthesis/Evaluation
23) Which of the following areas/conditions would be favored by thermophiles?
A) anaerobic conditions
B) deep-sea volcanic vents
C) the arctic tundra
D) the stomachs of herbivores
Answer: B
Topic: Section 21.6
Skill: Application/Analysis
24) In what type of environment would you be most likely to find anaerobes?
A) high temperature
B) high acidity
C) high salt content
D) no oxygen
Answer: D
Topic: Section 21.6
Skill: Knowledge/Comprehension
25) Which statement best describes our current understanding of protist evolution?
A) Protists evolved from the Archaea while other eukaryotes did not.
B) Protists evolved from multicellular eukaryotes.
C) Protists evolved from separate branches off the early eukaryotic line.
D) Protists evolved from eukaryotic parasites.
Answer: C
Topic: Section 21.7
Skill: Application/Analysis
26) An example of a protist intestinal parasite would be:
A) Clostridium botulinum.
B) Yersinia pestis.
C) Chlamydomonas.
D) Giardia.
Answer: D
Topic: Section 21.7
Skill: Knowledge/Comprehension
27) Plasmodium falciparum is a protozoan that:
A) can switch between plant and animal lifestyles.
B) is closely related to fungi.
C) causes malaria.
D) causes intestinal distress.
Answer: C
Topic: Section 21.7
Skill: Knowledge/Comprehension
28) What is the benefit of sexual reproduction in protists?
A) greater variation among offspring
B) fast increase in numbers
C) availability of more environments
D) ease of finding a mate
Answer: A
Topic: Section 21.8
Skill: Knowledge/Comprehension
29) A protist such as Chlamydomonas may switch to sexual reproduction when:
A) there are numerous predators.
B) there is little nutrition.
C) a 90-day cycle is completed.
D) hormones from nearby members of the species are detected.
Answer: B
Topic: Section 21.8
Skill: Knowledge/Comprehension
30) Chlamydomonas "mating types" differ in what way?
A) chloroplasts
B) flagella structure
C) interlocking male and female parts
D) membrane phospholipids
Answer: B
Topic: Section 21.8
Skill: Knowledge/Comprehension
31) Cells such as those of golden algae that form stable associations but do not take on specialized roles are described as:
A) incomplete unicellular.
B) selective multicellularity.
C) true multicellularity.
D) colonial multicellularity.
Answer: D
Topic: Section 21.9
Skill: Knowledge/Comprehension
32) Which organisms form the basic foundation of the food chain in the ocean?
A) shrimp
B) krill
C) phytoplankton
D) jellyfish
Answer: C
Topic: Section 21.9
Skill: Knowledge/Comprehension
33) Volvox and Paramecium share which characteristic?
A) photosynthetic ability
B) movement
C) true multicellularity
D) anaerobic respiration
Answer: B
Topic: Section 21.10
Skill: Application/Analysis
34) Amoeba and phytoplankton differ in that phytoplankton can:
A) perform photosynthesis.
B) eat krill.
C) move with pseudopodia.
D) live on land.
Answer: A
Topic: Section 21.10
Skill: Application/Analysis
35) Cilia are:
A) the cytoplasmic extensions or false feet that some cell types use for locomotion.
B) different kinds of cells, each designed to perform a different function.
C) the circular chromosomes of bacteria.
D) many short, hair-like cellular extensions that beat to produce movement.
Answer: D
Topic: Section 21.10
Skill: Knowledge/Comprehension
36) Entamoeba histolytica is a/an:
A) photosynthetic protist.
B) protist that moves using flagella.
C) parasitic protist responsible for dysentery.
D) aggregating protist that can form a "slug-like" organism.
Answer: C
Topic: Section 21.10
Skill: Knowledge/Comprehension
37) Organisms called plasmodial slime molds move by which process?
A) beating of cilia
B) cytoplasmic streaming
C) contractile cytoskeleton movements
D) growth in the direction of sunlight
Answer: B
Topic: Section 21.10
Skill: Knowledge/Comprehension
38) Bacteria are the smallest living things known.
Answer: TRUE
Topic: Section 21.1
Skill: Knowledge/Comprehension
39) Microscopic algae and bacteria produce over half of the oxygen in the atmosphere.
Answer: TRUE
Topic: Section 21.1
Skill: Knowledge/Comprehension
40) The core of some viruses is carbohydrate in nature.
Answer: FALSE
Topic: Section 21.2
Skill: Knowledge/Comprehension
41) Scientists do not consider viruses to be alive because viruses cannot metabolize outside a host cell.
Answer: TRUE
Topic: Section 21.2
Skill: Knowledge/Comprehension
42) When a virus takes over the machinery of a cell, it forces the cell to manufacture more viral particles.
Answer: TRUE
Topic: Section 21.2
Skill: Knowledge/Comprehension
43) Bacteria are considered to be a type of protist.
Answer: FALSE
Topic: Section 21.3
Skill: Knowledge/Comprehension
44) The simplest eukaryotes are the bacteria.
Answer: FALSE
Topic: Section 21.3
Skill: Knowledge/Comprehension
45) Some bacteria can obtain their nutrition by photosynthesis.
Answer: TRUE
Topic: Section 21.3
Skill: Knowledge/Comprehension
46) Spherical bacteria are called cocci.
Answer: TRUE
Topic: Section 21.3
Skill: Knowledge/Comprehension
47) Rod-shaped bacteria are called spirochetes.
Answer: FALSE
Topic: Section 21.3
Skill: Knowledge/Comprehension
48) Bacteria store their DNA within a spherical nucleus.
Answer: FALSE
Topic: Section 21.3
Skill: Knowledge/Comprehension
49) When bacteria undergo binary fission, they produce identical daughter cells.
Answer: TRUE
Topic: Section 21.3
Skill: Knowledge/Comprehension
50) Most bacteria present in the human intestines are pathogenic.
Answer: FALSE
Topic: Section 21.4
Skill: Application/Analysis
51) Nearly half the antibiotics used in the United States go into animal feed as growth stimulants.
Answer: TRUE
Topic: Section 21.5
Skill: Knowledge/Comprehension
52) Malaria is caused by a bacterium.
Answer: FALSE
Topic: Section 21.7
Skill: Knowledge/Comprehension
53) Most protists are unicellular.
Answer: TRUE
Topic: Section 21.7
Skill: Knowledge/Comprehension
54) A long, whip-like tail found in a protist is called a flagellum.
Answer: TRUE
Topic: Section 21.10
Skill: Knowledge/Comprehension
55) Paramecium is a heterotrophic protist that moves using cilia.
Answer: TRUE
Topic: Section 21.10
Skill: Knowledge/Comprehension
Match the following.
A) rod-shaped bacteria
B) structure found in many viruses, often "borrowed" from the host cell
C) round-shaped bacteria
D) organelle not found in both bacteria and eukaryotes
E) type of organelle found in both bacteria and eukaryotes
56) Nucleus
Topic: Section 21.3
Skill: Application/Analysis
57) Ribosome
Topic: Section 21.3
Skill: Application/Analysis
58) Coccus
Topic: Section 21.3
Skill: Knowledge/Comprehension
59) Fatty membrane called an envelope
Topic: Section 21.2
Skill: Knowledge/Comprehension
60) Bacillus
Topic: Section 21.3
Skill: Knowledge/Comprehension
Answers: 56) D 57) E 58) C 59) B 60) A
Match the following.
A) thermophile
B) anaerobe
C) halophile
D) pseudopod
E) heterotroph
61) "Other-eater"
Topic: Section 21.10
Skill: Knowledge/Comprehension
62) Thrives in salty environments
Topic: Section 21.6
Skill: Knowledge/Comprehension
63) Thrives in hot environments
Topic: Section 21.6
Skill: Knowledge/Comprehension
64) "False foot"
Topic: Section 21.10
Skill: Knowledge/Comprehension
65) Lives without oxygen
Topic: Section 21.6
Skill: Knowledge/Comprehension
Answers: 61) E 62) C 63) A 64) D 65) B
Match the following.
A) bubonic plague
B) "social amoeba"
C) a Type-A influenza
D) ciliated protist
E) truly multicellular algae
66) H1N1 virus
Topic: Section 21.2
Skill: Knowledge/Comprehension
67) The bacterium Yersinia pestis
Topic: Section 21.5
Skill: Knowledge/Comprehension
68) Dictyostelium discoideum
Topic: Section 21.10
Skill: Knowledge/Comprehension
69) Volvox
Topic: Section 21.9
Skill: Knowledge/Comprehension
70) Paramecium
Topic: Section 21.10
Skill: Knowledge/Comprehension
Answers: 66) C 67) A 68) B 69) E 70) D
71) Virus-like entities called viroids lack a ________ and are simply strands of infectious RNA.
Answer: capsid
Topic: Section 21.2
Skill: Knowledge/Comprehension
72) Overuse of antibiotics has likely produced MRSA. MRSA stands for ________.
Answer: methicillin-resistant Staphylococcus aureus
Topic: Section 21.5
Skill: Knowledge/Comprehension
73) Methanogens are in the ________ category of extremophile.
Answer: anaerobes
Topic: Section 21.6
Skill: Knowledge/Comprehension
74) Photosynthetic aquatic microorganisms, such as some bacteria and protists, are known as ________.
Answer: phytoplankton
Topic: Section 21.9
Skill: Knowledge/Comprehension
75) Some protists have locomotor extensions called ________ and ________.
Answer: cilia; flagella
Topic: Section 21.10
Skill: Knowledge/Comprehension
76) Scientists mostly agree that viruses are not technically living things. Defend this position based on what you know about what viruses are and how they work.
Answer: Although viruses are made of some of the same chemicals and undergo some of the same chemistry of living things, they possess too few of the necessary characteristics of life to qualify as a true living organism. They do reproduce, but only by using the biochemical machinery of the host cell. They have none of the other important characteristics of life and cannot perform any of the metabolic functions associated with life without a host cell. These are reasons why viruses should not be considered alive.
Topic: Section 21.2
Skill: Synthesis/Evaluation
77) Defend the position that bacteria are both beneficial and detrimental to humans.
Answer: On the one hand, bacteria degrade dead materials and return the organics to the soil. In the digestive tracts of humans, bacteria help make vitamins and materials available to humans. As part of the phytoplankton along with protists, bacteria produce an enormous amount of the oxygen for Earth's atmosphere. They have relationships with plants to help them fix nitrogen that plants need for metabolism and survival. On the other hand, some bacteria damage food crops and are responsible for causing disease and death in humans.
Topic: Section 21.6
Skill: Synthesis/Evaluation
78) Protists are arguably the most diverse of the eukaryotic kingdoms. Defend that statement using examples to support your ideas.
Answer: The protists include photosynthetic organisms, such as algae, as well as heterotrophic organisms, such as the Paramecium and Amoeba. Although protists are unicellular overall, some algae, such as Volvox, have evolved toward multicellular specialization. There are numerous free-living members of the kingdom, such as Amoeba proteus, and parasitic members, such as Entamoeba histolytica. Although most are microscopic, there are some, such as the slime molds, capable of forming large aggregates.
Topic: Section 21.10
Skill: Synthesis/Evaluation
Refer to the figure below, and then answer the following question(s).
79) The missing label indicated by a "1" corresponds to the:
A) receptor.
B) capsid.
C) RNA.
D) envelope.
Answer: B
Topic: Section 21.2
Skill: Knowledge/Comprehension
80) The missing label indicated by a "2" corresponds to the:
A) receptor.
B) capsid.
C) RNA.
D) envelope.
Answer: D
Topic: Section 21.2
Skill: Knowledge/Comprehension
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