Deck 19: Microbial Ecosystems

Question 1

Which is the CORRECT order of increasing size in soil particles?

A)clay > sand > silt
B)clay > silt > sand
C)sand > clay > silt
D)silt > clay > sand

Answer 1

B

Question 2

Which metric describes the proportion of EACH species present in a community?

A)species abundance
B)species diversity
C)species evenness
D)species richness

Answer 2

A

Question 3

In a stratified lake,the warmer and less dense layer is called the

A)epilimnion.
B)hypolimnion.
C)hyperlimnion.
D)thermocline.

Answer 3

A

Question 4

The chemical oxygen demand (COD)of a body of water is determined using a(n)

A)microelectrode.
B)oxygenator.
C)spectrophotometer to determine the OD₅₄₀nm.
D)strong oxidizing agent.

Question 5

The emergence of new microbial species because of geographic isolation is called ________ speciation.

A)allopatric
B)biogeochemical
C)biogeological
D)isolatory

Question 6

During periods of stratification,transfer between surface and bottom waters is controlled by

A)mixing.
B)diffusion.
C)niche partitioning.
D)current.

Question 7

Which of the following can function as intracellular signaling molecules?

A)acylated homoserine lactones
B)hydrophilic lipids
C)quinones
D)proteorhodopsins

Question 8

The generation time of Escherichia coli in the human intestine is ________ in laboratory culture.

A)at about the same rate as
B)faster than
C)more optimal than
D)slower than

Question 9

Which bacterial genus is responsible for producing ferrous iron (Fe²⁺)in groundwater?

A)Alteromonas
B)Aquifex
C)Geobacter
D)Loktanella

Question 10

Which metabolic strategy is MOST common in chemolithotrophic mats?

A)ammonia oxidation
B)iron oxidation
C)nitrate reduction
D)sulfur oxidation

Question 11

Assuming exposure to the same climate,which of the following aquatic systems would be MOST stratified?

A)20 m deep freshwater river
B)50 m deep marine water fjord
C)200 m deep saltwater lake
D)300 m deep freshwater lake

Question 12

A notorious biofilm former implicated in cystic fibrosis is

A)Bacillus subtilis.
B)Escherichia coli.
C)Lactobacillus acidophilus.
D)Pseudomonas aeruginosa.

Question 13

An organism living in the bottommost region of a body of water is described as being

A)benthic.
B)litoral.
C)neritic.
D)pelagic.

Question 14

Which of the following represents increasing microbial diversity?

A)guild-community-population
B)population-guild-community
C)cell-community-population
D)community-guild-population

Question 15

The photosynthetic pigments bacteriorhodopsin and proteorhodopsin are present in ________ and ________,respectively.

A)Archaea / Bacteria
B)Bacteria / Archaea
C)Bacteria / Bacteria
D)Bacteria / Eukarya

Question 16

A soil that lacks a dominate particle size is referred to as a(n)

A)aggregation.
B)bisequum.
C)loam.
D)mottled soil.

Question 17

Some nitrifying prokaryotes carry out metabolic cooperation by a process known as

A)competition.
B)niche partitioning.
C)syntrophy.
D)antagonism.

Question 18

Microenvironments of soil exist where ________ concentrations greatly vary.

A)oxygen
B)nitrate
C)sulfur
D)oxygen,nitrate,and sulfur

Question 19

According to bacterial abundance studies done so far on soils,the ________ represent the most abundant phylum.

A)Proteobacteria
B)Acidobacteria
C)Actinobacteria
D)Firmicutes

Question 20

The abundance of cyanobacterial mats has greatly declined due to the evolution of

A)antimicrobial-producing fungi.
B)bacteriophages.
C)metazoan grazers.
D)Proteobacteria.

Question 21

What is an average concentration of prokaryotic cells along the surface of pelagic water?

A)10⁴ cells/ml
B)10⁶ cells/ml
C)10⁸ cells/ml
D)10¹⁰ cells/ml

Question 22

________ are the main primary producers in freshwater environments.

A)Phototrophic microorganisms
B)Heterotrophic microorganisms
C)Chemolithotrophic microorganisms
D)Viral microorganisms

Question 23

Which are the MOST dominant chemolithotrophs in pelagic waters?

A)ammonia-oxidizing Archaea
B)ammonia-oxidizing Bacteria
C)sulfate-reducing Bacteria
D)Prochlorococcus

Question 24

Shallow marine sediments are dominated by

A)Firmicutes.
B)Planctomycetes.
C)Proteobacteria.
D)Tenericutes.

Question 25

Which of the following is NOT an oxygenic phototrophic microorganism present in marine waters?

A)Ostreococcus
B)Prochlorococcus
C)Roseobacter
D)Trichodesmium

Question 26

A chemical that comes from outside the ecosystem is referred to as a(n)________ chemical.

A)synthropic
B)lithotrophic
C)allochthonous
D)pleomorphic

Question 27

Epsilonproteobacteria are most dominant in hydrothermal vents because they

A)reduce nitrogen.
B)oxidize reduced sulfur compounds.
C)use oxygen as electron acceptors.
D)bind divalent cations.

Question 28

What adaptation do organisms have that tolerate high pressures?

A)decreased cell size
B)decreased lipid content
C)increased ribosome size
D)increased unsaturated fatty acids

Question 29

Sudden nutrient perturbations in an environment generally ________ the overall prokaryotic diversity.

A)increase
B)decrease
C)maintain
D)replicate

Question 30

A population of metabolically related microorganisms is called a(n)

A)guild.
B)niche.
C)ecosystem.
D)haplotype.

Question 31

Which of the following an example of a biofilm?

A)soap scum
B)dental plaque
C)marine diatom
D)planktonic microcolony

Question 32

From the aquatic systems below,where are heterotrophic Bacteria the MOST abundant?

A)coastal waters
B)deep sea
C)Sargasso Sea
D)open ocean

Question 33

The primary metal sulfides emitted from the black smokers are ________ sulfides.

A)copper
B)iron
C)magnesium
D)zinc

Question 34

Which statement is TRUE about the fluid from the hydrothermal vents?

A)The fluid contains large amounts of oxidized inorganic materials.
B)The fluid contains large amounts of reduced inorganic materials.
C)The fluid contains large amounts of organic material.
D)The fluid usually contains about equal amounts of organic and inorganic material.

Question 35

Sedimentation in bogs and marshes develop ________ soils.

A)inorganic
B)mineral
C)organic
D)loamy

Question 36

Archaea in pelagic deep-water are almost exclusively

A)Crenarchaeota.
B)Euryarchaeota.
C)Nanoarchaeota.
D)Thaumarchaeota.

Question 37

All Prochlorococcus strains contain

A)chlorophylls a and b.
B)chlorophyll a and phycobilins.
C)chlorophyll b and phycobilins.
D)chlorophylls a and b and phycobilins.

Question 38

Which aquatic habitat contains a pelagic zone?

A)estuary
B)lake
C)salt marsh
D)open ocean

Question 39

Ecological theory states that for every organism there is at LEAST one ________,and the microenvironment where the organism is MOST successful is called the ________.

A)population / community
B)niche / prime niche
C)prime niche / niche
D)community / population

Question 40

The number of Roseobacter in the ocean describes

A)species diversity.
B)species richness.
C)species abundance.
D)species prevalence.

Question 41

The microbial oxygen-consuming capacity of a water sample is called its

A)chemical oxygen demand.
B)biochemical capacity.
C)biochemical oxygen demand.
D)chemical capacity.

Question 42

Two major environmental extremes of the deep sea are high ________ and low ________.

A)pressure / nutrient levels
B)nutrient levels / pressure
C)temperature / pressure
D)oxygen / pressure

Question 43

Cyclic di-guanosine monophosphate is upregulated as Pseudomonas aeruginosa cells are declining.

Question 44

A microbial population can contain several microbial communities.

Question 45

Chemoheterotrophic bacteria are primary producers.

Question 46

________ use inorganic electron donors released from deep-sea hydrothermal vents.

A)Chemolithotrophs
B)Photoheterotrophs
C)Chemoheterotrophs
D)Photolithotrophs

Question 47

The physiochemical conditions of a microenvironment,by definition,remain static.

Question 48

Due to such an array of nutrients,microorganisms are often capable of sustaining exponential growth in the environment.

Question 49

The most abundant prokaryotic organism in the ocean is of the ________ genus.

A)Pelagibacter
B)Puniceispirillum
C)Roseobacter
D)Prochlorococcus

Question 50

Many microbial habitats are unsuitable for plants and animals.

Question 51

In the oceans,prokaryotes are outnumbered ten to one by

A)zooplankton.
B)diatoms.
C)viruses.
D)phytoplankton.

Question 52

Mineral soils largely come from weathered limestone and sand.

Question 53

Water in the rocks and soils of Earth's subsurface is called

A)groundwater.
B)surface water.
C)subsurface water.
D)deep water.

Question 54

Biomass generation due to heterotrophic organisms is called ________ production.

A)primary
B)secondary
C)auxotrophic
D)regulatory

Question 55

Cells within a biofilm excrete an adhesive matrix primarily composed of ________ but can also contain nucleic acids as well as proteins.

A)lipids
B)fatty acids
C)monomers
D)polysaccharides

Question 56

The formation of soil involves a combination of biological,chemical,and physical processes.

Question 57

An ecosystem includes both the living organisms and abiotic materials that function together.

Question 58

The cells within a biofilm can undergo intra-species signaling; however,inter-species signaling does not occur.

Question 59

Arid soils are among the most extreme environments on earth.

Question 60

Cyclic dimeric guanosine monophosphate (c-di-GMP)serves as a messenger molecule in bacterial cells to coordinate a shift from ________ to ________ growth.

A)sessile / planktonic
B)planktonic / sessile
C)monomorphic / polymorphic
D)stationary / exponential

Question 61

In the context of nutrients,a sink is one that slowly releases a particular nutrient over time.

Question 62

Unlike other cyanobacteria,Prochlorococcus lacks phycobilins.

Question 63

Low return of nutrients in the pelagic zone results in relatively low primary production in the open ocean when compared to freshwater lake systems.

Question 64

Distinguish an ecotype from a species,and provide an example of an ecotype.

Question 65

Archaea and Bacteria dominate the upper 100 m of the open ocean while viruses dominate depths greater than 100 m.

Question 66

Chemoorganotrophic bacteria can facilitate the formation of soil through the secretion of organic acids.

Question 67

Functional differences can be observed by using 16S rRNA gene phylogenetics of a microbial community.

Question 68

ALL stratified lakes contain a thermocline.

Question 69

Purple phototrophic bacteria that use bacteriochlorophyll a are oxygenic.

Question 70

In many marine systems,the carbon and oxygen cycles are directly proportional to each other.

Question 71

What is the difference between an organism being piezophilic and piezotolerant?

Question 72

Soil particles are classified based on their size.

Question 73

Oligotrophic organisms do NOT grow well under nutrient-replete conditions.

Question 74

Explain three reasons why bacteria form biofilms.

Question 75

Describe three molecular effects high pressure has on the physiology of organisms.

Question 76

Microbial life has been identified at depths of 3 km despite being anoxic.

Question 77

Provide a reason for the ecological importance of pelagic Bacteria and Archaea.

Question 78

Explain how both biochemical oxygen demand and chemical oxygen demand are measured.

Question 79

Gammaproteobacteria can be used for biodegradation of hydrocarbons.

Question 80

Limiting nutrients in soils are generally organic compounds.