Chapters 5, 6 + 7 - Nutrient Cycles

Question 1

What are producers?

Answer 1

Photosynthetic organisms that manufacture organic substances using light energy, water and carbon dioxide.

Question 2

What are consumers?

Answer 2

Organisms that obtain their energy by feeding on other organisms rather than using the energy of sunlight directly.

Question 3

What are decomposers?

Answer 3

Microorganisms that break down organic compounds in dead material and waste products into carbon dioxide, water and simple inorganic ions.

Question 4

What is a detritivore?

Answer 4

An animal which feeds on the pieces of partly broken down plant or animal tissue known as detritus. E.g. Earthworms and woodlice.

Question 5

What is the equation for net production?

Answer 5

Gross production - respiratory losses

Question 6

What is gross production?

Answer 6

The total quantity of energy that the plants in a community convert to organic matter.

Question 7

What is the equation for energy transfer?

Answer 7

(Energy available after the transfer / energy available before the transfer) X 100

Question 8

What is biomass?

Answer 8

The total dry mass of the plants and/or animals in a particular place. Measured in trams per square meter (g/m2).

Question 9

What is energy flow measured in?

Answer 9

kJ/m2/year

Question 10

What is an agricultural ecosystem?

Answer 10

Ecosystem based on domestic animals or crop plants.

Question 11

What is productivity?

Answer 11

The rate at which something is produced.

Question 12

What is gross productivity?

Answer 12

Rate at which plants assimilate chemical energy.

Question 13

What is a pest?

Answer 13

An organism that competes with humans for food or space.

Question 14

What is a pesticide?

Answer 14

A substance which is used to control pests.

Question 15

What is biological control?

Answer 15

The use of a pest’s natural predators or parasites to limit its population.

Question 16

What is integrated pest management?

Answer 16

Managing pests by combining the use of chemical pesticides and other methods of control.

Question 17

What is the carbon cycle?

Answer 17

The way in which the element carbon circulates or cycles in an ecosystem.

Question 18

What is the nitrogen cycle?

Answer 18

The way in which the element nitrogen circulates or cycles in an ecosystem.

Question 19

What is nitrification?

Answer 19

The conversion of ammonium compounds to nitrites and nitrates, by oxidation, with nitrifying bacteria.

Question 20

What is nitrogen fixation?

Answer 20

The incorporation of nitrogen gas in the atmosphere into organic nitrogen-containing compounds.

Question 21

What is ammonification?

Answer 21

Saprophytic micro organisms break down organic, nitrogen-containing substances into ammonium compounds.

Question 22

What is denitrification?

Answer 22

The conversion of nitrates to nitrogen gas by denitrifying bacteria - reduction and an anaerobic process.

Question 23

What is a fertiliser?

Answer 23

A substance which adds mineral ions to the soil.

Question 24

What is eutrophication?

Answer 24

The consequence of an increase in nutrients, especially nitrates and phosphates, in fresh water lakes and rivers. Often leads to a decrease in biodiversity.

Question 25

What is leaching?

Answer 25

The process by which nutrients are removed from the slim, usually by rainwater.

Question 26

What is succession?

Answer 26

The way in which the different species of organisms which make up a community change over a period of time.

Question 27

What is a pioneer species?

Answer 27

A species that an colonise bare rock or ground.

Question 28

What is conservation?

Answer 28

The management of the Earth’s natural resources in a way that maximises their use in the future.

Question 29

What is a climax community?

Answer 29

The different species of organisms that make up the final stage of ecological succession.