Community ecology (2)

Question 1

Define chemical cycling.

Answer 1

Chemical cycling is the transfer of matter within the ecosystem.

Question 2

How much energy stored at each trophic level is available for the next trophic level to use?

Answer 2

Only about 10% of the energy stored at each trophic level is available to the next level.

Question 3

Except for _________, there are no extraterrestrial sources of chemical elements.

Answer 3

Except for meteorites, there are no extraterrestrial sources of chemical elements.

Question 4

What does the biogeochemical cycle include?

Answer 4

Biogeochemical cycles include
-biotic components,
-abiotic components, and
-abiotic reservoirs, where chemicals accumulate or are stockpiled outside of living organisms

Question 5

What are the main water reservoirs?

Answer 5

Our main water reservoirs are standing bodies of water, oceans, and groundwater, and frozen in glaciers

Question 6

The carbon cycle depends on _______ and _______

Answer 6

The carbon cycle depends on photosynthesis and respiration

Question 7

What is the importance of carbon?

Answer 7

Carbon is the major ingredient of all organic molecules

Question 8

Where is the main reservoir of carbon?

Answer 8

Its main reservoir is in the atmosphere as carbon dioxide CO2 gas

Question 9

Explain the carbon cycle.

Answer 9

1. photosynthesis in plants, algae, and cyanobacteria removes carbon dioxide from the atmosphere.
2. Primary consumers and higher-level consumers release carbon dioxide through cellular respiration.
3. Plant litter, animal wastes, and death deteriorate into detritus.
4. The decomposers, or soil microbes that digest detritus release carbon dioxide into the air after decomposition.
   The burning of wood and fossil fuels also releases carbon dioxide into the atmosphere

Question 10

Why do we need phosphorus?

Answer 10

Organisms require phosphorus as an ingredient of
-nucleic acids
-Phospholipids
-ATP
-a mineral component of bones and teeth.

Question 11

The phosphorus cycle has an atmospheric component. True or false?

Answer 11

False. The phosphorus cycle does not have an atmospheric component

Question 12

What are the main reservoirs of phosphorus?

Answer 12

The main reservoirs of phosphorus are weathering rocks

Question 13

What is the limiting factor of the carbon cycle?

Answer 13

The fast rate at how consumers /decomposers get carbon back into the atmosphere

Question 14

What is the limiting factor of the phosphorus cycle?

Answer 14

The large of amount of time it takes for big rocks to weather down into small rocks and release phosphorus and the time it takes for sold rock formation

Question 15

What is the importance of nitrogen?

Answer 15

Nitrogen is:
-an ingredient of proteins and nucleic acids
-essential to the structure and functioning of all organisms
-a crucial and often limiting plant nutrient

Question 16

What are the reservoirs of nitrogen?

Answer 16

1. The atmosphere, of which about 80% is nitrogen gas (N2)
2. Soil.

Question 17

What is the limiting factor of the nitrogen cycle?

Answer 17

Nitrogen is in the atmosphere and plants can’t directly access it, unlike water and carbon.

Question 18

What is primary production and what is limited by?

Answer 18

In aquatic ecosystems, primary production (harnessing solar energy into chemical energy) is limited by low nutrient levels of phosphorus and nitrogen

Question 19

What is eutrophication?

Answer 19

Eutrophication is the process in which a water body becomes overly enriched with nutrients, leading to the plentiful growth of simple plant life.

Question 20

Why do humans depend on natural ecosystems?

Answer 20

-supply fresh water and some food
-recycle nutrients
-decompose wastes
regulate climate and air quality.