Deck 22: Biogeochemical Cycles

Question 1

Biological nitrogen fixation is accomplished by symbiotic ________ living in mutualistic association with plants.

Answer 1

bacteria

Question 2

Precipitation brings appreciable quantities of nutrients into ecosystems that are collectively called ________.

Answer 2

wetfall

Question 3

The difference between the rate of carbon uptake in photosynthesis and the rate of carbon loss due to autotrophic and heterotrophic respiration is the net ________ productivity.

Answer 3

ecosystem

Question 4

The nutrient ________ does not have a gaseous cycle because it occurs in only very minute amounts in the atmosphere.

Question 5

All nutrients flow from the nonliving, to the living, and back to the non-living components of the ecosystem in a path known as a(n)________ cycle.

Question 6

The main reservoirs of oxygen are water and ________.

Question 7

There are two basic types of biogeochemical cycles: gaseous and ________.

Question 8

The source of all carbon in both living organisms and fossil deposits is carbon ________ in the atmosphere and in all the waters of the Earth.

Question 9

The branch of chemistry dealing with the quantitative relationships of elements in combination is called ________.

Question 10

In aquatic ecosystems, the phosphorous cycle moves through three states: particulate organic phosphorous, dissolved organic phosphates, and ________ phosphates.

Question 11

In gaseous biogeochemical cycles, the main pools of nutrients are the atmosphere and the ________.

Question 12

The element ________ is a basic constituent of all organic compounds and is involved in the fixation of energy by photosynthesis.

Question 13

All but a small fraction of the Earth's ________ is buried in sedimentary rocks and is not actively involved in a global cycle.

Question 14

The major source of free oxygen that supports life on Earth is the ________.

Question 15

Nitrogen can be returned to the atmosphere when certain bacteria convert it from nitrate into nitrogen gas, which is a process called ________.

Question 16

________ is the most common form of nitrogen exported from terrestrial ecosystems in stream water.

Question 17

The ability of the surface waters of the ocean to take up carbon dioxide is governed by the reaction of carbon dioxide with the ________ ion to form bicarbonates.

Question 18

Nitrogen is available to plants in two forms: ammonium and ________.

Question 19

Compare and contrast biomagnification and bioaccumulation.

Question 20

The ________ is the largest pool of nitrogen.

Question 21

The flow of nutrients from the non-living to the living and back to the non-living components of an ecosystem is referred to as a(n)________ cycle.

A)trophic
B)biogeochemical
C)energy
D)life

Question 22

Carbon is released into the atmosphere as carbon dioxide as the result of the process of

A)photosynthesis.
B)primary production.
C)respiration.
D)fixation.

Question 23

Which of the following cycles is thought to be most under biological control?

A)oxygen
B)phosphorus
C)sulfur
D)lead

Question 24

The largest active carbon pool is

A)the atmosphere.
B)the oceans.
C)living organisms.
D)dead organisms.

Question 25

Much of the problem associated with forest die-back is a direct result of

A)high heavy metal levels.
B)denitrifying bacteria.
C)soil acidification.
D)global climate change.

Question 26

Biological nitrogen fixation is accomplished by

A)protozoans.
B)bacteria.
C)fungi.
D)plants.

Question 27

Which of the following nutrients is most closely linked to the energy cycle in ecosystems?

A)carbon
B)nitrogen
C)lead
D)sulfur

Question 28

In arctic ecosystems, ________ are used as bioindicators of heavy metal contamination.

A)polar bears
B)mosses and lichens
C)vascular plants
D)slugs and earthworms

Question 29

In ________ biogeochemical cycles, the main reservoirs of nutrients are the soil, rocks, and minerals.

A)sedimentary
B)gaseous
C)terrestrial
D)aquatic

Question 30

The source of all carbon in living organisms is

A)simple sugars.
B)carbon dioxide in the atmosphere and in water.
C)carbon-fixing bacteria.
D)sedimentary rocks.

Question 31

Which of the following does NOT provide an input of nitrogen into ecosystems?

A)atmospheric deposition
B)lightning
C)biological fixation by cyanobacteria
D)denitrification by soil bacteria

Question 32

________ contamination is a great concern in aquatic systems.

A)Pb
B)Cu
C)Al
D)Hg

Question 33

Which of the following is NOT a major reservoir for phosphorus?

A)the atmosphere
B)rocks
C)natural phosphate deposits
D)minerals

Question 34

Which of the following nutrients is produced by photosynthesis?

A)nitrogen
B)phosphorous
C)oxygen
D)sulfur

Question 35

Which of the following represents the largest natural source of sulfur gases released to the atmosphere?

A)volcanoes
B)terrestrial organisms
C)freshwater organisms
D)oceans

Question 36

In ________ biogeochemical cycles, the main reservoirs of nutrients are the atmosphere and the oceans.

A)sedimentary
B)gaseous
C)aquatic
D)terrestrial

Question 37

Which of the following nutrients has a cycle that does NOT contain an atmospheric phase?

A)carbon
B)nitrogen
C)phosphorus
D)sulfur

Question 38

Which of the following does NOT cause a loss of nutrients from an ecosystem?

A)the production of carbon dioxide during respiration
B)the addition of fertilizer to a crop field
C)the transport of organic matter by a river from one ecosystem to another
D)the harvesting of a crop by humans

Question 39

The largest pool of nitrogen is

A)the atmosphere.
B)the oceans.
C)living organisms.
D)dead organisms.

Question 40

Hydrogen sulfide is transformed into sulfate or elemental sulfur by

A)protozoans.
B)bacteria.
C)fungi.
D)algae.

Question 41

Carbon is exported to the atmosphere via the process of photosynthesis.

Question 42

Certain anaerobic bacteria are capable of converting nitrogen compounds into gaseous nitrogen.

Question 43

Without the cycling of water, biogeochemical cycles would cease.

Question 44

Carbon cycles more quickly through cold and dry ecosystems than it does through warm and wet ecosystems.

Question 45

Precipitation can be a significant input of nutrients in ecosystems.

Question 46

The biogeochemical cycles of one ecosystem are typically independent from those of other ecosystems.

Question 47

Carbon dioxide occurs in both the atmosphere and in oceans.

Question 48

Most carbon is buried in sedimentary rocks.

Question 49

In sedimentary biogeochemical cycles, the main reservoirs of nutrients are the atmosphere and the oceans.

Question 50

Of the carbon actively involved in the global cycle, most is in the oceans.

Question 51

There are two basic types of biogeochemical cycles: gaseous and sedimentary.

Question 52

Atmospheric carbon dioxide concentrations in a forest are greater during the day than during the night.

Question 53

Nutrients with a sedimentary cycle enter the ecosystem via the atmosphere.

Question 54

Seasonal fluctuations in atmospheric carbon dioxide concentrations are greater in the Northern Hemisphere than in the Southern Hemisphere.

Question 55

There is more carbon per unit of soil in cold polar regions than in the warm tropics.

Question 56

Atmospheric carbon dioxide concentrations are higher during summer than during winter.

Question 57

Ammonium and nitrate are forms of nitrogen that can be directly used by plants.

Question 58

Most plants obtain nitrogen directly from gaseous nitrogen in the atmosphere during respiration.

Question 59

The atmosphere is the largest pool of nitrogen.

Question 60

The phosphorus cycle is a sedimentary cycle with essentially no gaseous cycle.

Question 61

Outline possible anthropogenic influences on forest dieback.

Question 62

Stratospheric ozone shields the planet from biologically harmful ultraviolet radiation.

Question 63

In the era post-nuclear testing (after the 1950s), there was a movement to switch from breast-feeding to a formula diet due to the high levels of radiation in breast milk.

Question 64

Explain the difference between the two basic types of biogeochemical cycles, using specific examples of each.

Question 65

Describe how an atom of phosphorus might move from the crystal lattice of a mineral in a rock, through a plant, and into the ocean.

Question 66

The sulfur biogeochemical cycle is a sedimentary cycle with essentially no gaseous cycle.

Question 67

One way that sulfur enters the atmosphere is through volcanic activity.

Question 68

List and describe three different inputs of sulfur into the atmosphere.

Question 69

Atmospheric sulfur dioxide returns to Earth in rain as weak sulfuric acid.

Question 70

Describe three ways that nutrients can be lost from an ecosystem.

Question 71

Describe a pathway of nitrogen from the atmosphere into the body tissue of an herbivore.

Question 72

The main reservoir for phosphorus is organic matter in the soil.

Question 73

Oxygen is taken up by plants during photosynthesis.

Question 74

Oceans represent the largest natural source of sulfur gases released to the atmosphere.

Question 75

Describe how ozone is formed at different levels of the atmosphere and how biological organisms are affected by ozone.

Question 76

Oxygen is produced during respiration.

Question 77

Phosphorus is typically in short supply in aquatic and terrestrial ecosystems.

Question 78

Describe how atmospheric carbon dioxide levels fluctuate daily, seasonally, and geographically. Explain why such fluctuation occurs.

Question 79

The various biogeochemical cycles are largely independent of one another.