Question 1

Which of the following processes does denitrification contribute to?

Accepted Answer

A) acid rain 
B) ozone depletion 
C) global warming 
D) acid rain,ozone depletion,and global warming 
A) acid rain 
B) ozone depletion 
C) global warming 
D) acid rain,ozone depletion,and global warming D

Question 2

Mercury-resistant bacteria detoxify mercury by producing Hg⁰.

Accepted Answer

A) True 
 B)False  True

Question 3

Lysis of marine algae and cyanobacteria releases the major osmoregulatory solute,dimethylsulfoniopropionate (DMSP),which is degraded into the most abundant organic S compound in nature,________.

Accepted Answer

A) dimethyl sulfide (CH₃-S-CH₃) 
B) hydrogen sulfide (H₂S) 
C) gypsum (CaSO₄) 
D) elemental sulfur (Sᵒ) 
A) dimethyl sulfide (CH₃-S-CH₃) 
B) hydrogen sulfide (H₂S) 
C) gypsum (CaSO₄) 
D) elemental sulfur (Sᵒ) A

Question 4

How would Si depletion in the photic zone of the open ocean affect the biological pump and the C cycle?

Accepted Answer

Si is required for diatoms to fix carbon

Question 5

Using the sudden bloom of cyanobacteria in a lake due to anthropogenic fertilizer inputs as an example,explain the coupling of carbon,nitrogen,and oxygen cycling.Exclude discussion of all organisms other than microorganisms.

Accepted Answer

An increase in primary producers results

Question 6

Which iron species is produced primarily from iron smelting and rarely is produced by microbial-mediated processes?

Accepted Answer

A) ferric iron (Fe³⁺) 
B) ferrous iron (Fe²⁺) 
C) ferrulic iron (Fe¹⁺) 
D) iron (Fe⁰) 
A) ferric iron (Fe³⁺) 
B) ferrous iron (Fe²⁺) 
C) ferrulic iron (Fe¹⁺) 
D) iron (Fe⁰)

Question 7

Which is the MOST toxic form of mercury?

Accepted Answer

A) CH₃Hg⁺ 
B) Hg⁰ 
C) Hg²⁺ 
D) Hg⁴⁺ 
A) CH₃Hg⁺ 
B) Hg⁰ 
C) Hg²⁺ 
D) Hg⁴⁺

Question 8

Human activities have disrupted the carbon cycle by

Accepted Answer

A) burning carbon stored as fossil fuels or biomass,thus increasing the amount of carbon dioxide in the atmosphere. 
B) decreasing the primary productivity of the oceans,resulting in increased atmospheric carbon dioxide. 
C) burning methane hydrates to produce electricity. 
D) acidifying the ocean,resulting in the release of large amounts of dissolved carbon dioxide into the atmosphere. 
A) burning carbon stored as fossil fuels or biomass,thus increasing the amount of carbon dioxide in the atmosphere. 
B) decreasing the primary productivity of the oceans,resulting in increased atmospheric carbon dioxide. 
C) burning methane hydrates to produce electricity. 
D) acidifying the ocean,resulting in the release of large amounts of dissolved carbon dioxide into the atmosphere.

Question 9

When carbon is limiting in a system,sulfate reducers often predominate the system when sufficient sulfate ions are present for reduction.

Accepted Answer

A) True 
 B)False

Question 10

Humic acids are difficult to degrade,and therefore they usually remain in a system for several decades.

Accepted Answer

A) True 
 B)False

Question 11

Phosphorus reservoirs include

Accepted Answer

A) phosphate minerals in rocks,dissolved phosphates in aquatic environments,and the nucleic acids and phospholipids of living organisms. 
B) mineral phosphonates and the nucleic acids and phospholipids of living organisms. 
C) elemental phosphorus minerals and phosphonates. 
D) elemental phosphorous,polyphosphate,and phosphonates. 
A) phosphate minerals in rocks,dissolved phosphates in aquatic environments,and the nucleic acids and phospholipids of living organisms. 
B) mineral phosphonates and the nucleic acids and phospholipids of living organisms. 
C) elemental phosphorus minerals and phosphonates. 
D) elemental phosphorous,polyphosphate,and phosphonates.

Question 12

Diatoms require silicon due to their

Accepted Answer

A) Ca²⁺/Si⁴⁺ symporters. 
B) DNA replication mechanism. 
C) ornate frustules. 
D) unique phototrophic physiology. 
A) Ca²⁺/Si⁴⁺ symporters. 
B) DNA replication mechanism. 
C) ornate frustules. 
D) unique phototrophic physiology.

Question 13

Calcium is cycled most rapidly in terrestrial environments.

Accepted Answer

A) True 
 B)False

Question 14

Acetogens can ferment glucose into acetate,but methanogens cannot.

Accepted Answer

A) True 
 B)False

Question 15

Which statement exemplifies the biological pump concept?

Accepted Answer

A) Autotrophs bring in light photons to synthesize ATP. 
B) Bacteria oxidize Fe²⁺ into Fe³⁺,and Archaea reduce Fe³⁺ back into Fe²⁺. 
C) Calcium ions are brought into cells while toxic physiological byproducts are released. 
D) Primary producers sink to the deep ocean,which provides deep ocean organisms with nutrients when the primary producers die. 
A) Autotrophs bring in light photons to synthesize ATP. 
B) Bacteria oxidize Fe²⁺ into Fe³⁺,and Archaea reduce Fe³⁺ back into Fe²⁺. 
C) Calcium ions are brought into cells while toxic physiological byproducts are released. 
D) Primary producers sink to the deep ocean,which provides deep ocean organisms with nutrients when the primary producers die.

Question 16

Why is the water solubility of different nitrogen species of importance to agriculturalists? What processes in the nitrogen cycle are LEAST beneficial to agricultural production of crops?

Accepted Answer

If a particular nitrogen species is high

Question 17

Most chemolithotrophic bacteria that oxidize sulfur are aerobes.

Accepted Answer

A) True 
 B)False

Question 18

In a global sense,ALL nutrient cycles are coupled together.

Accepted Answer

A) True 
 B)False

Question 19

Bacterial oxidation of Fe²⁺ occurs BEST under which environmental condition?

Accepted Answer

A) cold temperature 
B) high sunlight 
C) low (acidic)pH 
D) nutrient-replete 
A) cold temperature 
B) high sunlight 
C) low (acidic)pH 
D) nutrient-replete

Question 20

Phosphonate comprises 25% of the ________ phosphorous pool in marine environments.

Accepted Answer

A) inorganic 
B) organic 
C) insoluble 
D) biologically unavailable 
A) inorganic 
B) organic 
C) insoluble 
D) biologically unavailable

Exam 20: Nutrient Cycles

Which of the following processes does denitrification contribute to?

Mercury-resistant bacteria detoxify mercury by producing Hg⁰.

Lysis of marine algae and cyanobacteria releases the major osmoregulatory solute,dimethylsulfoniopropionate (DMSP),which is degraded into the most abundant organic S compound in nature,________.

How would Si depletion in the photic zone of the open ocean affect the biological pump and the C cycle?

Using the sudden bloom of cyanobacteria in a lake due to anthropogenic fertilizer inputs as an example,explain the coupling of carbon,nitrogen,and oxygen cycling.Exclude discussion of all organisms other than microorganisms.

Which iron species is produced primarily from iron smelting and rarely is produced by microbial-mediated processes?

Which is the MOST toxic form of mercury?

Human activities have disrupted the carbon cycle by

When carbon is limiting in a system,sulfate reducers often predominate the system when sufficient sulfate ions are present for reduction.

Humic acids are difficult to degrade,and therefore they usually remain in a system for several decades.

Phosphorus reservoirs include

Diatoms require silicon due to their

Calcium is cycled most rapidly in terrestrial environments.

Acetogens can ferment glucose into acetate,but methanogens cannot.

Which statement exemplifies the biological pump concept?

Why is the water solubility of different nitrogen species of importance to agriculturalists? What processes in the nitrogen cycle are LEAST beneficial to agricultural production of crops?

Most chemolithotrophic bacteria that oxidize sulfur are aerobes.

In a global sense,ALL nutrient cycles are coupled together.

Bacterial oxidation of Fe²⁺ occurs BEST under which environmental condition?

Phosphonate comprises 25% of the ________ phosphorous pool in marine environments.

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viruses and Virology

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters