Question 1

Mercury can serve as a transcriptional activator in the regulation of certain genes.

Accepted Answer

A) True 
 B)False

Question 2

The largest reservoir of methane is found

Accepted Answer

A) trapped under permafrost and marine sediments. 
B) in the rumen of cows and other ruminant animals. 
C) in the atmosphere. 
D) trapped in volcanic rocks. 
A) trapped under permafrost and marine sediments. 
B) in the rumen of cows and other ruminant animals. 
C) in the atmosphere. 
D) trapped in volcanic rocks.

Question 3

Agricultural application of nitrogen fertilizer

Accepted Answer

A) reduces global warming by increasing the storage of carbon dioxide in plant biomass. 
B) increases global warming by increasing microbial respiration in agricultural soils. 
C) increases global warming by increasing the production of nitrous oxide (N₂O)by denitrification in agricultural soils. 
D) has little to no effect on the carbon cycle. 
A) reduces global warming by increasing the storage of carbon dioxide in plant biomass. 
B) increases global warming by increasing microbial respiration in agricultural soils. 
C) increases global warming by increasing the production of nitrous oxide (N₂O)by denitrification in agricultural soils. 
D) has little to no effect on the carbon cycle.

Question 4

Microbial activity generates methylmercury,which is much less toxic than the mercuric ion.

Accepted Answer

A) True 
 B)False

Question 5

How are the Ca cycle and the C cycle linked in marine environments? How will increased carbon dioxide from anthropogenic activity affect the Ca and C cycling in marine environments?

Accepted Answer

Several eukaryotic phototrophic microorg

Question 6

Energy yields are high enough for Fe²⁺ oxidation that the bacteria that perform this reaction require only small quantities of Fe²⁺ to be available.

Accepted Answer

A) True 
 B)False

Question 7

Silicoflagellates use silicon compounds in substrate-level phosphorylation.

Accepted Answer

A) True 
 B)False

Question 8

________ is a term used to describe dead organic matter.

Accepted Answer

A) Humus 
B) Loam 
C) Pyrite 
D) Xenocompost 
A) Humus 
B) Loam 
C) Pyrite 
D) Xenocompost

Question 9

Mercury is NOT used in

Accepted Answer

A) electronics. 
B) neurotoxins. 
C) pesticides. 
D) paper pulping. 
A) electronics. 
B) neurotoxins. 
C) pesticides. 
D) paper pulping.

Question 10

Most phosphorous,such as that found in inorganic phosphate (HPO₄⁻),exist in the +5 oxidation state in nature.

Accepted Answer

A) True 
 B)False

Question 11

Why is sulfur cycling more complex to study than other nutrient cycles such as the nitrogen cycle? How might this influence researchers whose primary research interest is in understanding sulfur cycling?

Accepted Answer

Most other nutrient cycles are either ex

Question 12

Nitrogen fixation results in the

Accepted Answer

A) loss of biologically available N from an ecosystem. 
B) formation of nitrogen gas. 
C) direct formation of nitrate. 
D) addition of biologically available N to an ecosystem. 
A) loss of biologically available N from an ecosystem. 
B) formation of nitrogen gas. 
C) direct formation of nitrate. 
D) addition of biologically available N to an ecosystem.

Question 13

The oxidation of ________ occurs both biotically and abiotically; however,at ________ pH values biotic oxidation is more common.

Accepted Answer

A) Si / low 
B) ammonia / high 
C) Fe²⁺ / low 
D) Hgᵒ / low 
A) Si / low 
B) ammonia / high 
C) Fe²⁺ / low 
D) Hgᵒ / low

Question 14

Coccolithophores and foraminiferans both use ________ to form their exoskeletons.

Accepted Answer

A) Si⁴⁺ 
B) Fe³⁺ 
C) Ca²⁺ 
D) HPO₄⁻ 
A) Si⁴⁺ 
B) Fe³⁺ 
C) Ca²⁺ 
D) HPO₄⁻

Question 15

Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming partner organism.

Accepted Answer

A) True 
 B)False

Question 16

In the oceans,sulfur exists primarily as ________,and in rocks and sediments sulfur occurs mostly as ________ and ________.

Accepted Answer

A) hydrogen sulfide (H₂S)/ gypsum (CaSO₄)/ elemental sulfur (Sᵒ) 
B) hydrogen sulfide (H₂S)/ sulfate (SO₄²⁻)/ elemental sulfur (Sᵒ) 
C) sulfate (SO₄²⁻)/ gypsum (CaSO₄)/ pyrite (FeS₂) 
D) sulfate (SO₄²⁻)/ sulfide (H₂S)/ elemental sulfur (Sᵒ) 
A) hydrogen sulfide (H₂S)/ gypsum (CaSO₄)/ elemental sulfur (Sᵒ) 
B) hydrogen sulfide (H₂S)/ sulfate (SO₄²⁻)/ elemental sulfur (Sᵒ) 
C) sulfate (SO₄²⁻)/ gypsum (CaSO₄)/ pyrite (FeS₂) 
D) sulfate (SO₄²⁻)/ sulfide (H₂S)/ elemental sulfur (Sᵒ)

Question 17

The metabolic process of ammonification ________ ammonia.

Accepted Answer

A) oxidizes 
B) produces 
C) reduces 
D) transforms 
A) oxidizes 
B) produces 
C) reduces 
D) transforms

Question 18

What are the similarities and differences between the Fe cycle and Ca cycle?

Accepted Answer

Both Fe and Ca cycle between insoluble a

Question 19

Marine wetlands (salt marshes)are highly productive coastal ecosystems that produce a lot of organic carbon,similar to freshwater wetlands; however,salt marshes smell very different than freshwater wetlands.What nutrient cycle is different between the two ecosystems that causes this difference in smell?

Accepted Answer

Salt marshes contain a lot more sulfur c

Question 20

What is the main form of nitrogen found on Earth?

Accepted Answer

A) N₂ 
B) NO 
C) NO₃⁻ 
D) NH₄ 
A) N₂ 
B) NO 
C) NO₃⁻ 
D) NH₄

Exam 20: Nutrient Cycles

Mercury can serve as a transcriptional activator in the regulation of certain genes.

The largest reservoir of methane is found

Agricultural application of nitrogen fertilizer

Microbial activity generates methylmercury,which is much less toxic than the mercuric ion.

How are the Ca cycle and the C cycle linked in marine environments? How will increased carbon dioxide from anthropogenic activity affect the Ca and C cycling in marine environments?

Energy yields are high enough for Fe²⁺ oxidation that the bacteria that perform this reaction require only small quantities of Fe²⁺ to be available.

Silicoflagellates use silicon compounds in substrate-level phosphorylation.

________ is a term used to describe dead organic matter.

Mercury is NOT used in

Most phosphorous,such as that found in inorganic phosphate (HPO₄⁻),exist in the +5 oxidation state in nature.

Why is sulfur cycling more complex to study than other nutrient cycles such as the nitrogen cycle? How might this influence researchers whose primary research interest is in understanding sulfur cycling?

Nitrogen fixation results in the

The oxidation of ________ occurs both biotically and abiotically; however,at ________ pH values biotic oxidation is more common.

Coccolithophores and foraminiferans both use ________ to form their exoskeletons.

Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming partner organism.

In the oceans,sulfur exists primarily as ________,and in rocks and sediments sulfur occurs mostly as ________ and ________.

The metabolic process of ammonification ________ ammonia.

What are the similarities and differences between the Fe cycle and Ca cycle?

What is the main form of nitrogen found on Earth?

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

The oxidation of occurs both biotically and abiotically; however,at pH values biotic oxidation is more common.

In the oceans,sulfur exists primarily as ,and in rocks and sediments sulfur occurs mostly as and .