Chapter 17 Bacteria And Archaea Test Bank

Chapter 17

Bacteria and Archaea

Multiple Choice Questions

1. Biofilms are organized aggregates of bacteria that may
2. form when bacteria settle and reproduce on a solid surface.
3. communicate with one another.
4. form structures with specialized functions.
5. protect one another.
6. All of the answer choices are correct.
7. Bacterial biofilms are important medically because they
8. All of the answer choices are correct.
9. can create resistance to treatment with antibiotics.
10. can form dental plaque.
11. may form on catheters.
12. are resistant to immune defenses.
13. Of the following, which is found in eukaryotes but not found among prokaryotes, such as bacteria and archaea?
14. ribosomes
15. membrane-bound organelles
16. cell membrane
17. single-celled organisms
18. chromosomes
19. A prokaryote that occupies a habitat consisting of a low pH is a(n)
20. basophile.
21. hydrophile.
22. thermophile.
23. halophile.
24. acidophile.

5. A prokaryote that occupies an extremely salty habitat is a(n)

1. basophile.
2. thermophile.
3. halophile.
4. hydrophile.
5. acidophile.

6. A prokaryote that occupies a habitat that is characterized by extreme heat (above 50 degrees Celsius) is a(n)

1. acidophile.
2. thermophile.
3. halophile.
4. hydrophile.
5. basophile.

7. The domains that contain prokaryotes are

1. Archaea, Bacteria, and Eukarya.
2. None of the answer choices is correct.
3. Archaea and Eukarya.
4. Archaea and Bacteria.
5. Bacteria and Eukarya.

8. Using an electron microscope, you observe bacterial cells from an environmental sample. You view a region of the bacterial cells that contains

the chromosome. You identify and label the region as the

1. cell wall.
2. cell membrane. C. nucleoid.
3. ribosome.
4. nucleus.

9. Circular DNA that is apart from the chromosome DNA in some prokaryotes is called a(n)

1. endospore.
2. nucleoid.
3. ribosome.
4. plasmid.
5. nucleus.
6. In prokaryotes, the structure that assembles proteins is the
7. endospore.
8. cell membrane.
9. ribosome.
10. lysosome.
11. plasmid.
12. The rigid barrier that surrounds most prokaryotes is the
13. cell wall.
14. cytoplasm.
15. glycocalyx.
16. cell membrane.
17. flagellum.
18. The Gram stain distinguished bacteria into two types of cells. This stain is dependent on the amount of in the cell wall
19. glucose
20. a complex lipid
21. cellulose
22. peptidoglycan
23. chitin
24. Which of the following is not a function of the glycocalyx in prokaryotes?
25. protein synthesis
26. attachment
27. resistance to drying
28. protection from immune system cells
29. production of biofilms
30. The structures of prokaryotes that are used to transfer DNA from one cell to another are
31. endospores.
32. cilia.
33. flagella.
34. attachment pili.

E. sex pili.

1. aid in locomotion of some prokaryotes.
2. Cilia
3. Flagella
4. Glycocalyx
5. Pili
6. Peptidoglycan
7. An endospore is an important internal structure for some bacteria in that it
8. allows for attachment to surfaces.
9. allows the organism to become dormant and survive harsh conditions.
10. is involved in cellular reproduction.
11. is the site of DNA for specific cell functions.
12. involved in genetic mutation for future generations.
13. An asexual process used by prokaryotes, in which replicated DNA and other cell parts are distributed into two daughter cells, is called
14. daughter cell duplication.
15. conjugation.
16. meiosis.
17. mitosis.
18. binary fission.
19. A type of horizontal gene transfer in prokaryotes, in which a cell takes up naked DNA without cell-to-cell contact, is

A. transduction.

B. fixation.

1. conjugation.
2. transformation.
3. replication.
4. A type of horizontal gene transfer in prokaryotes, in which a cell receives DNA from another cell through a sex pilus, is
5. replication.
6. fixation.
7. transduction.
8. transformation.
9. conjugation.
10. A type of horizontal gene transfer in prokaryotes, in which a cell receives bacterial DNA from a bacteriophage, is
11. fixation.
12. transformation.
13. replication.
14. transduction.
15. conjugation.
16. The three most common shapes of prokaryotes are
17. cubical, spherical, and rod-shaped.
18. rod-shaped, star-shaped, and cubical.
19. spherical, spiral, and thread-like.
20. star-shaped, cubical, and spherical.
21. spherical, rod-shaped, and spiral.
22. A microbiologist Gram stains a bacterium and finds the bacterium to be pink to red in color. This identifies the
23. bacterium as disease-causing organism.
24. species of bacterium.
25. bacterium as gram-positive.
26. bacterium as gram-negative.
27. bacterium as an endospore former.
28. A microbiologist Gram stains a bacterium and finds the bacterium to be blue to purple in color. This identifies the
29. bacterium as gram-positive.
30. bacterium as a disease-causing organism.
31. bacterium as an endospore former.
32. species of bacterium.
33. bacterium as gram-negative.
34. Chloroplasts and mitochondria have relatively small, circular chromosomes. This observation is evidence which supports the endosymbiotic theory, proposing that chloroplasts and mitochondria arose from which of the following
35. naked DNA
36. other eukaryotic cells
37. viruses
38. protists
39. bacteria
40. Cyanobacteria can derive nutritional carbon molecules by consuming those from other organisms, or by producing them from inorganic carbon (atmospheric CO2) through photosynthesis. In which of the following ecological groups would they also be considered?

A. obligate anaerobes

B. both heterotrophic and autotrophic

1. chemotrophic
2. autotrophic
3. heterotrophic
4. Clostridium tetani, the bacterium that causes tetanus, can only survive in soil away from oxygen. It is considered which of the following?
5. an autotroph
6. an obligate anaerobe
7. a facultative anaerobe
8. aerobic
9. a phototroph
10. Clostridium tetani, the bacterium that causes tetanus, can survive in soil for up to 40 years. Forming which of the following structures would support its longevity?
11. a glycocalyx
12. a pilus
13. a cell wall
14. an endospore
15. a cell membrane
16. Escherichia coli and Salmonella can live in our intestines in the presence or absence of oxygen. They are considered which of the following?
17. autotrophs
18. facultative anaerobes
19. obligate anaerobes
20. aerobic
21. phototrophs
22. Escherichia coli and Salmonella can remain in one location in our intestines. They would most likely contain which of the following?
23. flagella
24. spirochetes
25. glycocalyx
26. pili
27. cilia
28. Botox is a toxin produced by the bacterium Clostridium botulinum. When ingested with tainted food, botox can cause distress by paralyzing the intestines, and, in high doses, can kill by paralyzing muscles needed for breathing and heartbeating. Why would botox be an adaptation for Clostridium botulinum?
29. Botox allows the bacteria to gain more oxygen
30. Botox prevents other bacteria from entering the gut.
31. Botox prevents antibiotics from entering the gut.
32. Botox allows the bacteria to gain more food.
33. Botox prevents the intestines from removing the bacteria.

31. Vibrio cholera is the cause of cholera, and has a single flagellum stretching off from one end. A characteristic of this organism should be an ability to

1. move within its liquid habitat.
2. attach to cells in the host organism's intestines.
3. transmit DNA to other bacteria.
4. avoid ingestion by cells in the immune system.
5. induce a large antibody response.

32. Infections by Helicobacter pylori cause 90% of peptic ulcers in the United States. These bacteria have pili that are only expressed in acidic conditions. A characteristic of this organism should be an ability to

A. avoid ingestion by cells in the immune system.

B. enter the bloodstream.

1. attach to cells in the host organism's stomach.
2. induce a large antibody response.
3. move in the direction opposite the pili.
4. Mycobacterium tuberculosis is an obligate aerobe. In which organ would you expect to find these bacteria?
5. lung
6. intestines
7. liver
8. brain
9. kidney
10. Streptomyces are aerobic soil bacteria that produce over two-thirds of our antibiotics. Why might a bacterium produce antibiotics?
11. to kill competing bacteria of the same species
12. to protect itself from a host immune system
13. to kill viruses that may try to infect it
14. to allow it to break down the cell walls of plants
15. to kill competing bacteria of different species
16. Prokaryotes lack which of the following?
17. DNA
18. a cell membrane
19. a cell wall
20. RNA
21. a nucleus
22. Which of the following is true of a gram-positive bacterium, and not of a gram-negative bacterium?
23. It has a thick cell membrane.
24. It is more likely to trigger an immune response and cause inflammation and fever.
25. It has a nucleus.
26. It is larger, and thus weighs more grams.
27. Its cell wall is made of a thick layer of peptidoglycan.
28. Methicillin is a medicine that inhibits cell wall production. Why does this make it a suitable antibiotic for eliminating bacterial infections in humans?
29. Human cells do not have cell walls.
30. Human cells and bacterial cells are completely different, so methicillin does not affect human cells.
31. All humans have a gene giving methicillin resistance.
32. Human cells have a plasma membrane in addition to the cell wall that allows them to survive in the presence of methicillin.
33. The cell wall of human cells is not sensitive to methicillin.
34. One way that antibiotic-resistant strains of bacteria arise is that patients do not follow the instructions for taking the drug. In a typical scenario, a drug may be prescribed for a week, but the patient may stop taking it after 2 to 3 days if they start to feel better. Then when the infection flares up again, they take the rest of their dose. Why would this scenario lead to drug resistance?
35. The first round of treatment gives the bacteria a chance to learn how to metabolize the drug.
36. A patient begins to develop resistance to the drug.
37. The body clears the drug faster, once it is exposed a second time.

D. The first round of treatment does not kill the most resistant bacteria, which then increase in number.

E. The first round of treatment suppresses the immune system, making the patient more susceptible to other infections.

1. Bacteria and archaea use the same four bases in their DNA as eukaryotes. This supports which of the following statements?
2. All three domains arose from a common ancestor.
3. DNA was the original genetic material.
4. Bacteria, archaea, and eukaryotes contain the same set of genes.
5. DNA evolved independently at least three times.
6. Bacteria, archaea, and eukaryotes could interbreed.

True / False Questions

1. Streptomyces are aerobic soil bacteria that produce over two-thirds of our antibiotics of natural origin. These antibiotics should also be effective in killing Streptomyces.

True False

1. Streptomyces are obligate aerobic soil bacteria that infect many plant roots, causing scabs on their leaves. You would expect to find more

Streptomyces near the surface of the soil.

True False

1. Antibiotics usually are not dangerous to use in treating bacterial infections because most antibiotics exploit structures and functions in bacteria that are not present in host cells.

True False

1. Pili are bacterial structures used primarily for motility.

True False

1. Autotrophs must acquire carbon from organic molecules produced from other organisms.

True False

1. Heterotrophs must acquire carbon from organic molecules produced from other organisms.

True False

1. An organism to which oxygen is toxic is an obligate anaerobe.

True False

1. Because Archaea were first found in environments that lacked oxygen or were very hot, acidic, or salty, they were nicknamed "extremophiles."

True False

1. The main difference between gram-positive bacteria and gram-negative bacteria is in the structure of their cell membranes.

True False

1. Many prokaryotes play vital roles in global nutrient cycles.

True False

1. Most bacteria inside and on the human body cause diseases.

True False