Matter, Energy, and Food Webs

Question 0

What is the amount of biomass that is available to consumers at subsequent tropic levels?

Answer 0

Net primary production

Question 1

What is the total amount of organic material produced by plants?

Answer 1

Gross primary production

Question 2

What is the amount of biomass at higher graphic levels known as?

Answer 2

Secondary production

Question 3

What is the percentage of energy transferred from one trophic level to the next, that varies between 5% and 20%, called?

Answer 3

Ecological efficiency

Question 4

What is the original source of energy that powers ecosystems?

Answer 4

The sun

Question 5

What law states that the total energy content of a trophic level is only one-tenth of the preceding level?

Answer 5

10% law

Question 6

What is the measure of the total leaf area of a given plant?

Answer 6

Leaf Area Index

Question 7

What is the gain in mass or plant tissue per unit in time known as?

Answer 7

Relative growth rate

Question 8

What is the formula for relative growth rate?

Answer 8

Increase in dry mass per unit in time/

Original dry mass of plant

Question 9

What is the increase in plant weight per unit of leaf area per unit time?

Answer 9

Net Assimilation Rate

Question 10

What is the difference between productivity and production?

Answer 10

Productivity is a rate, whereas production is total energy

Question 11

Why is the net primary production of open ocean ecosystems low in comparison to that of coastal systems?

Answer 11

Water reflects or absorbs much of the sun’s energy before it reaches producers.

Question 12

What is the constant mass of a dried plant material?

Answer 12

Standing crop

Question 13

What is the biological origin of coal?

Answer 13

Plant matter

Question 14

What is the biological origin of oil?

Answer 14

Algae

Question 15

What is the biological origin or limestone?

Answer 15

Tiny shells and other bits of skeletons

Question 16

What three processes release carbon into the atmosphere?

Answer 16

Combustion, cellular respiration, and volcanic activity

Question 17

What bacteria fixes atmospheric nitrogen?

Answer 17

Azotobacter

Question 18

What bacteria converts Ammonia to Nitrite?

Answer 18

Nitosomonas sp.

Question 19

What bacteria converts nitrite to nitrate?

Answer 19

Nitrobacter spp.

Question 20

What bacteria releases nitrogen back into the atmosphere?

Answer 20

Denitrifying bacteria

Question 21

What bacteria turn nitrogen back into Ammonia?

Answer 21

Nitrogen-fixing cyanobacteria

Question 22

What three processes fix atmospheric nitrogen?

Answer 22

Microbial fixation, Haber Process, and lightning.

Question 23

What process releases nitrogen gas into the atmosphere?

Answer 23

Denitrification

Question 24

In what form is most nitrogen available to plants?

Answer 24

Nitrate (NO3)

Question 25

How do animals get the Nitrogen they need?

Answer 25

By eating plants and herbivores

Question 26

Why might farmers plough a crop of legumes into the ground rather than harvest it?

Answer 26

Legumes restore Nitrogen to the soil by increasing bacteria count.

Question 27

What are five ways humans intervene with the Nitrogen cycle?

Answer 27

Haber Process, irrigation and harvesting crops, burning crops, using pesticides, crop rotation.

Question 28

What are the two ways water returns to the oceans from land?

Answer 28

Precipitation and runoff

Question 29

What are three ways humans intervene with the water cycle?

Answer 29

Deforestation, the building of dams, the creation of non-permeable surfaces

Question 30

What is the main reservoir for water on earth?

Answer 30

Oceans

Question 31

What are the earth's main reservoir's for freshwater?

Answer 31

Lakes, aquifers, glaciers, and rivers

Question 32

What role do plants play in the hydrologic cycle?

Answer 32

They transpire, creating humidity.

Question 33

What are two instances in the Phosphorus cycle where bacterial action is important?

Answer 33

Chemical waste and fertilization

Question 34

What are the three forms of inorganic phosphate that make up the geological reservoir?

Answer 34

Rock phosphates, insoluble phosphates, and dissolved phosphates.

Question 35

What must occur to make rock phosphate available to plants?

Answer 35

Weathering

Question 36

What are two ways in which Sulfur can enter the atmosphere from natural sources?

Answer 36

Volcanic activity and hot springs

Question 37

What are two ways in which sulfur can enter the atmosphere as a result of human activity?

Answer 37

Combustion of fossil fuels and smelting

Question 38

What three processes make sulfur available for uptake by plants?

Answer 38

Decomposition of decayed matter, acid precipitation drops sulfate into the soil, conversion of hydrosulfic acid to sulfate by microorganisms.

Question 39

What are two major roles of Sulfur in the biosphere?

Answer 39

Increases the Earth's albedo, makes up key components in proteins