Ch 32

Question 1

Any microorganism that spends a portion of its life associated with another organism of a different species is engaged in 
A. symbiosis.
B. synergy.
C. parasitism.
D. commensalism.

Answer 1

A. symbiosis.

Question 2

Which of the following is not a category of symbiosis? 
A. mutualism
B. phoresis
C. commensalism
D. parasitism

Answer 2

B. phoresis

Question 3

In commensalism
A. the host and commensal can be separated and remain viable.
B. the commensal is metabolically dependent on the host.
C. the host provides some factor that the commensal cannot get otherwise.
D. the host and commensal cannot be separated and remain viable and the commensal is metabolically dependent on the host.
E. all of these.

Answer 3

A. the host and commensal can be separated and remain viable.

Question 4

In mutualism
A. the mutualist is dependent on the host.
B. a reciprocal benefit accrues to both partners.
C. the partners will not survive separately in many cases.
D. all of these

Answer 4

D. all of these

Question 5

Which of the following is not part of the lichen association? 
A. ascomycetes
B. green algae
C. brown algae
D. cyanobacteria

Answer 5

C. brown algae

Question 6

In a lichen, the fungal partner
A. protects the alga from excess light intensities.
B. provides water and minerals to the alga.
C. provides a substratum within which the alga grows.
D. all of these

Answer 6

D. all of these

Question 7

The reason coral reefs are among the most productive and successful ecosystems is due to
A. the coral-dinoflagellate mutualistic relationship.
B. the lichen mutualistic relationship.
C. commensalisms.
D. all of these

Answer 7

A. the coral-dinoflagellate mutualistic relationship.

Question 8

In the rumen, food is quickly attacked by cellulase
A. enzymes produced by the ruminant.
B. enzymes produced by microbes.
C. enzymes produced by both the ruminant and the microbe.
D. archeons.

Answer 8

B. enzymes produced by microbes.

Question 9

In the rumen, the carbohydrate fermentation end products include 
A. acetate.
B. carbon dioxide.
C. methane.
D. all of these

Answer 9

D. all of these

Question 10

In lichens, the fungi send projections of their hyphae across the algal cell wall in order to obtain nutrients from the photosynthetic partner. These projections are called 
A. mycelia.
B. hyphal extensions.
C. haustoria.
D. lichenthropes.

Answer 10

C. haustoria.

Question 11

The ectosymbionts of ruminant animals are useful to their hosts in which of the following ways?
A. They digest the cellulose of plant cell walls.
B. They produce most of the vitamins needed by the ruminant.
C. They convert glucose to organic acids.
D. all of the choices

Answer 11

D. all of the choices

Question 12

A physical relationship where an organism hosts more than one symbiont is known as a 
A. clade.
B. consortium.
C. partnership.
D. cojoining.

Answer 12

B. consortium.

Question 13

Buchnera aphidicola provides \_\_\_\_\_\_\_\_\_\_\_ to its aphid host that are essential to the survival of the insect. 
A. carbohydrates
B. vitamins
C. amino acids
D. cellulases

Answer 13

C. amino acids

Question 14

The rickettsial parasite Wolbachia pipientis can
A. sometimes alter the sex of an infected wasp.
B. confer toxicity to the sting of an infected wasp.
C. enhance the life-span of an infected wasp.
D. none of the choices

Answer 14

A. sometimes alter the sex of an infected wasp.

Question 15

Dinoflagellates that exist endosymbiotically within a variety of marine invertebrates are called 
A. endoflagellates.
B. parasites.
C. endotrophic.
D. zooxanthellae.

Answer 15

D. zooxanthellae.

Question 16

Mussels and sponges sometimes contain methanotrophs as intracellular symbionts because the methanotrophs
A. remove otherwise toxic levels of methane from the environment.
B. convert methane to carbohydrate for use by the host.
C. allow the partnership to use hydrogen sulfide as a source of electrons.
D. all of the choices

Answer 16

B. convert methane to carbohydrate for use by the host.

Question 17

Riftia tube worms make a unique kind of hemoglobin to
A. transport oxygen.
B. transport hydrogen sulfide.
C. to assist in the transport of carbon dioxide.
D. all of the choices

Answer 17

D. all of the choices

Question 18

The filamentous bacteria that grow on the dorsal surface of certain polychaete worms
A. fend off potential predators with toxins.
B. carry out photosythesis.
C. may provide the worm with protection from toxic metals.
D. all of the choices

Answer 18

C. may provide the worm with protection from toxic metals.

Question 19

When Nitrobacter utilizes nitrite produced from ammonia by Nitrosomonas to obtain energy by converting the nitrite to nitrate, the relationship between the two organisms is 
A. commensal.
B. amensal.
C. mutual.
D. parasitic.

Answer 19

A. commensal.

Question 20

Methanogens are always engaged in relationships with other microbes because methane production requires
A. removal of oxygen from the environment by another microbe.
B. energy provided by another microbe.
C. interspecies hydrogen transfer.
D. none of the choices

Answer 20

C. interspecies hydrogen transfer.

Question 21

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a predator that bores a hole through the outer membrane of its gram-negative bacterial prey and then reproduces in the periplasm. 
A. Vampirococcus
B. Bdellovibrio
C. Daptobacter
D. Syntrophobacter

Answer 21

B. Bdellovibrio

Question 22

A unidirectional process where a specific compound released by one organism has a negative effect on another organism is called 
A. predation.
B. commensalism.
C. negative cooperation.
D. amensalism.

Answer 22

D. amensalism.

Question 23

Pseudonocardia is an organism that is hosted by 
A. wood-eating insects.
B. marine invertebrates.
C. ants that cultivate fungal gardens.
D. people with severe acne.

Answer 23

C. ants that cultivate fungal gardens.

Question 24

\_\_\_\_\_\_\_\_\_\_\_\_ arises when different microbes within a population or community try to acquire the same resource. 
A. Amensalism
B. Competition
C. Disruption
D. Syntropism

Answer 24

B. Competition

Question 25

Microbes such as Lactobacillus acidophilus colonize the human vagina by fermenting 
A. glycogen.
B. glucose.
C. lactose.
D. sucrose.

Answer 25

A. glycogen.

Question 26

The average adult carries 10 times more microbial cells (10^14) than human cells (average about 10^13). T/F

Answer 26

TRUE

Question 27

Microorganisms commonly associated with the human body are traditionally referred to as the
A. normal microbial flora.
B. normal microbes.
C. normal microbiota.
D. normal microbial flora or the normal microbiota.

Answer 27

D. normal microbial flora or the normal microbiota.

Question 28

A species of bacterium associated with the oil glands of the skin belongs to the genus 
A. Staphylococcus.
B. Pityrosporum.
C. Propionibacterium.
D. Pityrosporum.

Answer 28

C. Propionibacterium.

Question 29

Which of the following would you not find in the nasopharynx? 
A. Streptococcus pneumoniae
B. Neisseria meningitidis
C. Haemophilus influenzae
D. Branhamella catarrhalis

Answer 29

D. Branhamella catarrhalis

Question 30

Which of the following would you expect to find in the tonsilar crypts? 
A. Micrococcus
B. Staphylococcus
C. Streptococcus
D. Neisseria

Answer 30

A. Micrococcus

Question 31

Microbiota of the skin are most likely to be found
A. where there is little moisture.
B. where the pH of the skin secretions is below 4.
C. in association with oil and sweat glands.
D. all of the choices

Answer 31

C. in association with oil and sweat glands.

Question 32

Under normal circumstances, the microbiota of the skin is kept in check by 
A. a high pH (above 8).
B. a slightly acidic pH.
C. phagocytic activity.
D. excessive moisture.

Answer 32

B. a slightly acidic pH.

Question 33

A bacterial genus that is found in large numbers in the intestinal tract of breast-fed infants is 
A. Bacteroides.
B. Bifidobacteria.
C. Escherichia.
D. Doderlein's bacillus.

Answer 33

B. Bifidobacteria.

Question 34

Which of the following areas of the human body is(are) not normally free of microorganisms? 
A. respiratory tract
B. intestinal tract
C. eyes
D. all of the choices

Answer 34

D. all of the choices

Question 35

The lungs are protected from microorganisms by
A. the ciliated epithelial cells.
B. lysozyme in mucus.
C. phagocytic action of alveolar macrophages.
D. all of these

Answer 35

D. all of these

Question 36

Human sweat has antimicrobial activity due to
A. production of an antimicrobial peptide called cathelicidins.
B. competition with normal sweat gland flora.
C. production of low molecular weight compounds that maintain an alkaline pH.
D. production of low molecular weight compounds that chelate free iron.

Answer 36

A. production of an antimicrobial peptide called cathelicidins.

Question 37

Gram-positive bacteria such as Propionibacterium acnes limit the growth of gram-negative bacteria and some fungi on the human skin by converting secreted \_\_\_\_\_\_\_\_\_\_ to compounds with antimicrobial activity. 
A. lipids
B. organic acids
C. salts
D. urea

Answer 37

A. lipids

Question 38

When members of the normal microbiota of the human body become pathogenic and produce disease under certain circumstances, they are referred to as \_\_\_\_\_\_\_\_\_\_\_\_\_\_ pathogens. 
A. partial
B. conditional
C. occasional
D. opportunistic

Answer 38

D. opportunistic