Topic 2 - Ecosystems and Ecology

Question 1

Species?

Answer 1

A group of organisms sharing common characteristics that interbreed and produce fertile offspring

Question 2

Habitat?

Answer 2

The environment in which a species normally lives

Question 3

Niche?

Answer 3

Describes the particular set of biotic and abiotic conditions and resources to which an organism or population responds

Question 4

Fundamental niche?

Answer 4

Describes the full range of conditions and resources in which a species could survive and reproduce

Question 5

Realised niche?

Answer 5

Describes the actual conditions and resources in which a species exists due to its biotic interactions

Question 6

Abiotic factors?

Answer 6

The non-living, physical factors that influence the organisms and ecosystems, e.g. temperature, sunlight, ph, salinity

Question 7

Biotic factors?

Answer 7

The interactions between the organisms, e.g. predation, herbivory, parasitism, mutualism, disease and competition

Question 8

What is a population?

Answer 8

A group of organisms of the same species living in the same area at the same time and which are capable of interbreeding

Question 9

What are S and J population curves?

Answer 9

These are used to describe a generalised response of populations to a particular set of conditions (abiotic and biotic factors)

Question 10

Limiting factors?

Answer 10

Factors which slow down growth of a population as it reaches its carrying capacity

Question 11

Carrying capacity?

Answer 11

The maximum number of a species or ‘load’ that can be sustainably supported by a given area

Question 12

Predation?

Answer 12

When one animal, the predator, eats another animal, the prey

Question 13

Herbivory?

Answer 13

An animal (herbivore) eating a green plant

Question 14

Parasitism?

Answer 14

A relationship between two species in which one species lives in or on another, gaining its food from it

Question 15

Mutualism?

Answer 15

A relation between two or more species in which all benefit and none suffer

Question 16

Community?

Answer 16

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

Question 17

Ecosystem?

Answer 17

A community and the physical environment it interacts with

Question 18

Respiration?

Answer 18

Conversion of organic matter into CO2 and water in all living organisms, releasing energy

Question 19

Photosynthesis?

Answer 19

Produces the raw material for producing biomass

Question 20

Trophic level?

Answer 20

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 21

Producers (autotrophs)?

Answer 21

Plants or algae that produce their own food using photosynthesis and form the first tropic level of a food chain

Question 22

Ecological pyramids?

Answer 22

Pyramids of numbers, biomass and productivity and are quantitative models, usually measured for a given area and time

Question 23

Bioaccumulation?

Answer 23

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

Question 24

Biomagnification?

Answer 24

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

Question 25

Productivity?

Answer 25

The conversion of energy into biomass for a given period of time

Question 26

Net primary productivity?

Answer 26

Subtract respiration losses from gross primary productivity

Question 27

Gross secondary productivity?

Answer 27

Total energy / biomass assimilated by consumers calculated by subtracting the mass of fecal loss from the mass of food eaten

Question 28

Net secondary productivity?

Answer 28

Subtract respiration losses from gross secondary productivity

Question 29

Maximum sustainable yields?

Answer 29

Equivalent to the net primary or net secondary productivity of a system

Question 30

Energy subsidy?

Answer 30

Additional energy that we have to put into a system above that which comes from the sun (e.g. human labour, animal labour, fuel)

Question 31

Biomes?

Answer 31

Collections of ecosystems sharing similar climatic conditions. Each will have characteristic limiting factors, biodiversity and productivity.

Question 32

Zonation?

Answer 32

Changes in a community along an environmental gradient due to factors such as changes in altitude, latitude, tidal level or distance from shore

Question 33

Succession?

Answer 33

The process of change over time in an ecosystem involving pioneer, intermediate and climax communities

Question 34

Tricellular model of atmospheric circulation?

Answer 34

Explains the distribution of precipitation and temperature influencing biomes

Question 35

Pioneer species?

Answer 35

First species to colonize an area - r strategists (can be plant or animal life)

Question 36

Primary succession?

Answer 36

Occurs on a bare inorganic surface. Involves the colonisation of newly created land by organisms. It occurs as new land is either created or uncovered such as river deltas, after volcanic eruptions, on sand dunes.

Question 37

Secondary succession?

Answer 37

Where an already established community is suddenly destroyed, such as following fire or flood or even human activity (ploughing)