2. Ecosystems and ecology

Question 1

Species

Answer 1

a group of organisms that interbreed and can produce fertile offspring

Question 2

Population

Answer 2

a group of organisms of the same species living in the same area at the same time and which can interbreed

Question 3

Habitat

Answer 3

the environment in which a species normally lives

Question 4

Niche

Answer 4

the particular set of abiotic and biotic conditions and resources that an organism responds to

Question 5

Fundamental niche

Answer 5

the full range of conditions and resources where a species could survive and reproduce

Question 6

Realised niche

Answer 6

the actual conditions and resources that a species exists in due to biotic interactions

Question 7

Abiotic factor (and examples)

Answer 7

non living, physical factors that influence organisms/ecosystems like temperature, sunlight, pH, salinity, precipitation

Question 8

Biotic factor

Answer 8

interactions between the organisms such as predation, herbivory, parasitism, mutualism, disease, competition

Question 9

Competition

Answer 9

a common demand by 2 or more organisms for a limited supply of a resource like food, water, light, space

Question 10

Carrying capacity

Answer 10

the maximum number of a species or load that can be sustainably supported by a given environment

Question 11

Biosphere

Answer 11

The part of the earth inhabited by organisms

Question 12

Ecosystem

Answer 12

A community and the physical environment with which it interacts

Question 13

Community

Answer 13

A group of populations living and interacting with each other in a common habitat

Question 14

Trophic level

Answer 14

The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains

Question 15

Bioaccumulation

Answer 15

The build-up of persistent or non-biodegradable pollutants within an organism or trophic level because they can’t be broken down

Question 16

Biomagnification

Answer 16

The increase in concentration of persistent or non-biodegradable pollutants along a food chain.

Question 17

Gross productivity (GP)

Answer 17

total gain in energy per unit area per unit time (e.g through photosynthesis in primary producers)

Question 18

Net productivity (NP)

Answer 18

the gain in energy per unit area per unit time remaining after allowing for respiratory losses (R)

Question 19

Primary productivity

Answer 19

Gain by producers in energy per unit area per unit time (can refer to GP or NP)

Question 20

Secondary productivity

Answer 20

the biomass gained by consumers through feeding and absorption (measured in units of mass or energy per unit area per unit time)

Question 21

Gross primary productivity (GPP)

Answer 21

total gain in energy per unit time fixed by photosynthesis in green plants

Question 22

Net primary productivity (NPP)

Answer 22

subtracting respiratory losses (R) from GPP

Question 23

Gross Secondary productivity (GSP)

Answer 23

The total gain by consumers in energy or biomass per unit area per unit time through absorption

Question 24

Net secondary productivity (NSP)

Answer 24

The gain by consumers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses

Question 25

Sustainable yield

Answer 25

when a natural resource can be harvested at a rate equal to or less than its natural productivity so that the natural capital is not diminished

Question 26

Biome

Answer 26

A collection of ecosystems sharing similar climatic conditions- for example, tundra, tropical rainforest and desert.

Question 27

Latitude

Answer 27

The angular distance from the equator (north or south of it) as measured from the centre of the earth (usually in degrees)

Question 28

Succession

Answer 28

The orderly process of change over time in a community

Question 29

K strategists

Answer 29

Species that usually concentrate their reproductive investment in a small number of offspring, thus increasing their survival rate and adapting them for living in long-term climax communities

Question 30

R strategists

Answer 30

Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonise new habitats rapidly and make opportunistic use of short-lived resources.

Question 31

Zonation

Answer 31

The arrangement or patterning of plant communities or ecosystems into parallel bands in response to change, over a distance, in some environmental factor

Question 32

Motile organism

Answer 32

organism that can actively move under its own power from place to place

Question 33

Non-motile organism

Answer 33

one that cannot move or can only move very very slowly (limpets on rocky shore)

Question 34

Biomass

Answer 34

The mass of organic material in organisms or ecosystems, usually stated per unit area.

Question 35

Diversity

Answer 35

a generic term for variation. can refer to species, habitat or gene diversity.