Campbell Biology : Concepts and Connections

Jane B. Reece, Martha R. Taylor, Eric J. Simon

Chapter 16

Microbial Life: Prokaryotes and Protists - all with Video Answers

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Chapter Questions

Problem 1

Explain how each of the following characteristics contributes to the success of prokaryotes: cell wall, capsule, flagella, fimbriae, endospores.

Alexander Cheng

Alexander Cheng

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Problem 2

Fill in the blanks on the phylogenetic tree to show current hypotheses for the origin of multicellular organisms. (FIGURE CAN'T COPY)

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 3

In terms of nutrition, autotrophs are to heterotrophs as
a. kelp are to diatoms.
b. archaea are to bacteria.
c. slime molds are to algae.
d. algae are to slime molds.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 4

A new organism has been discovered. Tests have revealed that it is unicellular, is autotrophic, and has a cell wall that contains peptidoglycan. Based on this evidence, it should be classified as a(n)
a. alga.
b. archaean.
c. protist.
d. bacterium.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 5

Which pair of protists has support structures composed of silica?
a. dinoflagellates and diatoms
b. diatoms and radiolarians
c. radiolarians and forams
d. forams and amoebozoans

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 6

Which of the following members of the SAR supergroup is incorrectly paired with its clade?
a. stramenopiles-brown algae
b. alveolates-parasites such as Plasmodium
c. alveolates - dinoflagellates
d. Rhizaria-diatoms

Carly Hill

Numerade Educator

Problem 7

Which of the following prokaryotes is not pathogenic?
a. Chlamydia
b. Rhizobium
c. Streptococcus
d. Salmonella

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 8

Explain why prokaryote populations can adapt rapidly to changes in their environment.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 9

What characteristic distinguishes true multicellularity from colonies of cells?

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 10

Chlamydomonas is a unicellular green alga. How does it differ from a photosynthetic bacterium, which is also single-celled? How does it differ from a protozoan, such as an amoeba? How does it differ from larger green algae, such as sea lettuce (Ulva)?

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 11

The bacteria that cause tetanus can be killed only by prolonged heating at temperatures considerably above boiling. This suggests that tetanus bacteria
a. have cell walls containing peptidoglycan.
b. secrete endotoxins.
c. are autotrophic.
d. produce endospores.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 12

Which of the following experiments could test the hypothesis that bacteria cause ulcers in humans? (Assume each experiment includes a control group). Explain what evidence would be provided by the results of the experiment.
a. Identify the microbes found in the stomachs of ulcer patients.
b. Treat a group of ulcer patients with antibiotics.
c. Place a group of ulcer patients on a strict low-acid diet.
d. Obtain stomach fluid from ulcer patents and feed it to mice.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 13

Euglena (an excavate) and Gymnodinium (an alveolate) are both capable of photosynthesis. However, researchers have identified differences in their chloroplasts. Use the theory of endosymbiosis to explain the reason for these differences. (Hint: Review Figure 16.13.)

Abigail Schammel

Abigail Schammel

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Problem 14

Probiotics, foods and supplements that contain living microorganisms, are thought to cure problems of the digestive tract by restoring the natural balance of its microbial community. Sales of these products total billions of dollars a year. Explore the topic of probiotics and evaluate the scientific evidence for their beneficial effects. A good starting point is the website of the U.S. Food and Drug Administration, which regulates advertising claims of health benefits of dietary supplements (www.fda.gov/Food/DietarySupplements/default .htm. Source U.S. Food and Drug Administration website, $2013 .)$

Dennis Howard

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Problem 15

Imagine you are on a team designing a moon base that will be self-contained and self-sustaining. Once supplied with building materials, equipment, and organisms from Earth, the base will be expected to function indefinitely. One of the team members has suggested that everything sent to the base be sterilized so that no bacteria of any kind are present. Do you think this is a good idea? Predict some of the consequences of eliminating all bacteria from an environment.

Yokshitha Reddy Bathula

Yokshitha Reddy Bathula

Numerade Educator

Problem 16

The buildup of $\mathrm{CO}_{2}$ in the atmosphere resulting from the burning of fossil fuels is regarded as a major contributor to global warming (see Module 38.3 ). Diatoms and other microscopic algae in the oceans counter this buildup by using large quantities of atmospheric $\mathrm{CO}_{2}$ in photosynthesis, which requires small quantities of iron. Experts suspect that a shortage of iron may limit algal growth in the oceans. Some scientists have suggested that one way to reduce $\mathrm{CO}_{2}$ buildup might be to fertilize the oceans with iron. The iron would stimulate algal growth and thus the removal of more $\mathrm{CO}_{2}$ from the air. A single supertanker of iron dust, spread over a wide enough area, might reduce the atmospheric $\mathrm{CO}_{2}$ level significantly. Do you think this approach would be worth a try? Why or why not?

Emily Marty

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