Question 1

The zone of soil that surrounds the roots and contains a variety of organic exudates is called the

Accepted Answer

A)   mycorrhizae.
B)   rootsphere.
C)   rhizosphere.
D)   geosmin.E) None of the above
F) All of the above

Question 2

Streptomyces

Accepted Answer

A)   may produce antibiotics.
B)   may produce geosmins.
C)   will swarm together to form fruiting bodies.
D)   are typically found in the soil.
E)   may produce antibiotics, may produce geosmins AND are typically found in the soil.F) All of the above
G) C) and D)

Question 3

Streptomyces produces geosmins which give soil a characteristic musty odor.

Accepted Answer

A) True 
 B)False

Question 4

Biofilms are likely to be found in environments

Accepted Answer

A)   that are nutrient rich.
B)   that are relatively warm.
C)   with rapidly flowing water.
D)   with low nutrients.E) B) and D)
F) B) and C)

Question 5

Fungi are able to handle acidic environments much better than bacteria.

Accepted Answer

A) True 
 B)False

Question 6

The organisms that convert carbon dioxide into organic matter are the

Accepted Answer

A)   secondary consumers.
B)   primary consumers.
C)   producers.
D)   decomposers.E) A) and B)
F) A) and D)

Question 7

A microbial mat

Accepted Answer

A)   is a form of biofilm.
B)   is poorly organized.
C)   contains only obligate anaerobes.
D)   is constructed to prevent interactions between the various layers of microorganisms.
E)   is a form of biofilm AND is poorly organized.F) A) and E)
G) B) and D)

Question 8

The problem of not being able to cultivate most microorganisms has led to the use of

Accepted Answer

A)  FISH.
B)   microscopy with fluorescent dyes.
C)  16s rRNA analysis.
D)  DGGE.
E)  All of these methods help identify microorganisms in the environment.F) C) and D)
G) A) and E)

Question 9

In many aquatic habitats, the growth of algae and cyanobacteria is limited by the amount of

Accepted Answer

A)   nitrogen.
B)   calcium.
C)   sulfur.
D)   phosphorus.E) B) and D)
F) B) and C)

Question 10

Which of the following soil organisms play a major role in decomposing plant matter?

Accepted Answer

A)   bacteria
B)   fungi
C)   protozoa
D)   viruses
E)   bacteria AND fungiF) C) and D)
G) A) and D)

Question 11

Which group is composed of autotrophs?

Accepted Answer

A)   primary producers
B)   primary consumers
C)   secondary consumers
D)   decomposersE) B) and C)
F) A) and D)

Question 12

Nutrient poor waters are described as being

Accepted Answer

A)   hypoxic.
B)   oligotrophic.
C)   autotrophic.
D)   eutrophic.E) A) and B)
F) C) and D)

Question 13

Next to carbon and oxygen, the element organisms most require is

Accepted Answer

A)   sulfur.
B)   phosphorus.
C)   nitrogen.
D)   iron.E) All of the above
F) None of the above

Question 14

During aerobic decomposition of organic matter the primary gas produced is

Accepted Answer

A)   oxygen.
B)   hydrogen sulfide.
C)   nitrogen.
D)   carbon dioxide.E) A) and B)
F) B) and C)

Question 15

How can the biomass of fungi in soil be greater considering that bacteria are more numerous?

Accepted Answer

A)   Fungi are always multicellular organisms, while bacteria are unicellular. As such, biomass of fungi would always be larger than that of bacteria, since they possess more cells in each individual organism.
B)   This is a matter of size. Fungi, whether unicellular or multicellular, are eukaryotic. As such, they will generally be larger than bacteria (which are prokaryotic) . This means that, even with a lower overall number, they will have more total biomass.
C)   It depends on where they grow. Fungi generally grow in the most moist areas near the top of soil. This gives them an advantage over bacteria. They may not be as numerous, but this advantage in location and nutrients is what makes them larger than the bacteria (and therefore having more biomass) . If the bacteria evolved to take over the top portion of the soil, THEY would have the larger biomass than the fungi.
D)   Fungi are capable of incorporating the dead materials around them into themselves as nutrient sources (while bacteria are not) . This capacity allows them to greatly increase their biomass per each organism, well beyond what a simple bacterial cell could hold. This capability is what allows them to achieve higher biomass than bacteria.E) A) and D)
F) A) and C)

Question 16

No eukaryotic organisms have been shown to fix nitrogen without the aid of prokaryotes.

Accepted Answer

A) True 
 B)False

Question 17

The organisms isolated from hydrothermal vents are typically

Accepted Answer

A)   phototrophs.
B)   chemolithoautotrophs.
C)   rhizobia.
D)   bacteroid.
E)   phototrophs, rhizobia AND bacteroid.F) B) and D)
G) D) and E)

Question 18

The bacteria cultured from a soil sample typically represents

Accepted Answer

A)   all the bacteria present in that sample.
B)   a very small number of bacteria present in that sample.
C)   all the metabolically active bacteria.
D)   all the metabolically inactive bacteria.E) A) and B)
F) A) and C)

Question 19

Oligotrophic waters are usually hypoxic.

Accepted Answer

A) True 
 B)False

Question 20

A mycorrhizae is a symbiotic association between roots and fungi.

Accepted Answer

A) True 
 B)False

Exam 29: Microbial Ecology

No eukaryotic organisms have been shown to fix nitrogen without the aid of prokaryotes.

Correct AnswerverifiedShow Answer

Oligotrophic waters are usually hypoxic.

Correct AnswerverifiedShow Answer

Biofilms are likely to be found in environments

Correct AnswerverifiedShow Answer

The organisms that convert carbon dioxide into organic matter are the

Correct AnswerverifiedShow Answer

Which of the following soil organisms play a major role in decomposing plant matter?

Correct AnswerverifiedShow Answer

In many aquatic habitats, the growth of algae and cyanobacteria is limited by the amount of

Correct AnswerverifiedShow Answer

Next to carbon and oxygen, the element organisms most require is

Correct AnswerverifiedShow Answer

How can the biomass of fungi in soil be greater considering that bacteria are more numerous?

Correct AnswerverifiedShow Answer

The problem of not being able to cultivate most microorganisms has led to the use of

Correct AnswerverifiedShow Answer

The bacteria cultured from a soil sample typically represents

Correct AnswerverifiedShow Answer

Streptomyces produces geosmins which give soil a characteristic musty odor.

Correct AnswerverifiedShow Answer

Fungi are able to handle acidic environments much better than bacteria.

Correct AnswerverifiedShow Answer

Streptomyces

Correct AnswerverifiedShow Answer

A microbial mat

Correct AnswerverifiedShow Answer

During aerobic decomposition of organic matter the primary gas produced is

Correct AnswerverifiedShow Answer

The organisms isolated from hydrothermal vents are typically

Correct AnswerverifiedShow Answer

Which group is composed of autotrophs?

Correct AnswerverifiedShow Answer

A mycorrhizae is a symbiotic association between roots and fungi.

Correct AnswerverifiedShow Answer

Nutrient poor waters are described as being

Correct AnswerverifiedShow Answer

The zone of soil that surrounds the roots and contains a variety of organic exudates is called the

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified