Deck 19: Microbial Ecosystems

Question 1

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

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

Answer 1

C

Question 2

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 2

B

Question 3

A notorious biofilm former implicated in cystic fibrosis is

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

Answer 3

D

Question 4

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

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

Question 5

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

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

Question 6

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 7

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

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

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

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

Question 10

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 11

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 12

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 13

Which metabolic strategy is MOST common in chemolithotrophic mats?

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

Question 14

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 15

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

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

Question 16

Which of the following can function as intracellular signaling molecules?

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

Question 17

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

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

Question 18

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

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

Question 19

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 20

Microenvironments of soil exist where ________ concentrations greatly vary.

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

Question 21

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

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

Question 22

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

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

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

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

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

Question 25

Sedimentation in bogs and marshes develop ________ soils.

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

Question 26

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 27

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 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

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 30

________ are the main primary producers in freshwater environments.

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

Question 31

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

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

Question 32

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 33

Which aquatic habitat contains a pelagic zone?

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

Question 34

Archaea in pelagic deep-water are almost exclusively

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

Question 35

Which of the following an example of a biofilm?

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

Question 36

The number of Roseobacter in the ocean describes

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

Question 37

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 38

Shallow marine sediments are dominated by

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

Question 39

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

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

Question 40

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 41

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

Question 42

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

Question 43

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 44

Arid soils are among the most extreme environments on earth.

Question 45

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

Question 46

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

Question 47

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 48

In the oceans,prokaryotes are outnumbered ten to one by

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

Question 49

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

Question 50

A microbial population can contain several microbial communities.

Question 51

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 52

Many microbial habitats are unsuitable for plants and animals.

Question 53

Mineral soils largely come from weathered limestone and sand.

Question 54

Biomass generation due to heterotrophic organisms is called ________ production.

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

Question 55

Chemoheterotrophic bacteria are primary producers.

Question 56

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

Question 57

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

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

Question 58

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 59

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

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

Question 60

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

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

Question 61

Unlike other cyanobacteria,Prochlorococcus lacks phycobilins.

Question 62

Limiting nutrients in soils are generally organic compounds.

Question 63

Gammaproteobacteria can be used for biodegradation of hydrocarbons.

Question 64

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

Question 65

Purple phototrophic bacteria that use bacteriochlorophyll a are oxygenic.

Question 66

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

Question 67

Explain three reasons why bacteria form biofilms.

Question 68

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

Question 69

ALL stratified lakes contain a thermocline.

Question 70

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

Question 71

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

Question 72

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 73

Soil particles are classified based on their size.

Question 74

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

Question 75

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

Question 76

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

Question 77

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

Question 78

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

Question 79

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

Question 80

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