Topic 7 - Ecology

Question 1

Abiotic factors

Answer 1

The non-living aspects of an ecosystem e.g. temperature, light intensity,
moisture, wind direction, wind intensity, soil pH, soil mineral content, carbon dioxide levels
and oxygen levels.

Question 2

Adaptation

Answer 2

A feature of an organism that increases its chance of survival in its environment.
Such features may be behavioural, structural or functional.

Question 3

Anaerobic decay

Answer 3

Decomposition in the absence of oxygen (commonly occurring in
waterlogged soils) that produces carbon dioxide and methane gas.

Question 4

Apex predator

Answer 4

A carnivore at the top of the food chain with no predators.

Question 5

Biodiversity

Answer 5

The variety of living organisms in an ecosystem.

Question 6

Biogas

Answer 6

A type of biofuel (methane gas) produced by anaerobic decay in biogas generators.

Question 7

Biotic factors

Answer 7

The living components of an ecosystem e.g. food availability, pathogens,
predators and other species.

Question 8

Carbon cycle

Answer 8

The cycle through which carbon (in the form of carbon dioxide) moves
between living organisms and the environment, involving respiration, photosynthesis and
combustion.

Question 9

Community

Answer 9

All of the populations of different species living together in a habitat.

Question 10

Competition

Answer 10

When different organisms compete for the same resources (e.g. light, water,
mates, territory) in an ecosystem. This limits population sizes and stimulates evolutionary change.

Question 11

Compost

Answer 11

Dead and decaying organic matter, commonly used as a fertiliser.

Question 12

Decomposers

Answer 12

Organisms that release enzymes which catalyse the breakdown of dead
plant and animal material into simpler organic matter.

Question 13

Decomposition

Answer 13

The breakdown of dead materials into simpler organic matter. The rate of
decomposition is affected by temperature, water and oxygen availability.

Question 14

Distribution

Answer 14

The spread of living organisms in an ecosystem. It is affected by
environmental changes which may be seasonal, geographic or man-made.

Question 15

Ecosystem

Answer 15

The community of organisms (biotic) and non-living (abiotic) components of an
area and their interactions.

Question 16

Extremophiles

Answer 16

Organisms that can live in extreme environments e.g. high temperatures,
high salinity.

Question 17

Food chain

Answer 17

Describes the feeding relationships between organisms and the resultant
stages of biomass transfer.
It takes the form:
producer ⟶
primary consumer ⟶
secondary consumer ⟶
tertiary consumer

Question 18

Food security

Answer 18

Ensuring that populations have access to adequate amounts of safe and
nutritious food.

Question 19

Global warming

Answer 19

The gradual rise in the average temperature of the Earth due to increasing
atmospheric levels of carbon dioxide and methane gas.

Question 20

GM crops

Answer 20

Crops that have had their genomes modified by the insertion of a desired gene
from another organism.

Question 21

Interdependence

Answer 21

The dependence of different organisms on each other for survival e.g.
plants depend on pollinators, herbivores depend on plants.

Question 22

Microorganisms

Answer 22

Very small organisms involved in the recycling of materials in an ecosystem. They return mineral ions to the soil and convert carbon to carbon dioxide which is released into the atmosphere.

Question 23

Mycoprotein

Answer 23

A food high in protein (suitable for vegetarians) that is produced by the
microorganism, Fusarium, in fermentation vats.

Question 24

Peatlands

Answer 24

Areas of peat soil in wetland habitats formed by the accumulation of partially
decayed organic matter. Peat is commonly used as a garden compost.

Question 25

Pollution

Answer 25

Contamination or destruction of the natural environment due to human intervention.

Question 26

Population

Answer 26

All organisms of the same species living with one another in a habitat.

Question 27

Predators

Answer 27

Consumers that prey on and eat other animals.

Question 28

Prey

Answer 28

Animals that are eaten by predators.

Question 29

Primary consumers

Answer 29

Herbivores that consume producers at trophic level 2 of a food chain.

Question 30

Producers

Answer 30

Photosynthetic organisms (e.g. green plant or alga) at the start of the food chain that provide biomass for all living things.

Question 31

Pyramid of biomass

Answer 31

A table of the dry mass of living material at each trophic level of a food chain. This forms the shape of a pyramid.

Question 32

Quadrat

Answer 32

A square grid of known area used in sampling to determine the abundance and distribution of organisms in an ecosystem.

Question 33

Secondary consumers

Answer 33

Carnivores that consume herbivores at trophic level 3 of a food chain.

Question 34

Sustainable

Answer 34

The ability to maintain something for future generations.

Question 35

Sustainable fisheries

Answer 35

Methods of harvesting fish at a sustainable rate and increasing fish stocks, for example, by controlling net size or introducing fishing quotas.

Question 36

Tertiary consumers

Answer 36

Carnivores that consume other carnivores at trophic levels 4 and above of a food chain.

Question 37

Transect

Answer 37

A line along an area used in sampling to determine the abundance and distribution of organisms in an ecosystem.

Question 38

Trophic level

Answer 38

The position of an organism in a food chain.

Question 39

Water cycle

Answer 39

The cycle through which water moves between living organisms and the environment, involving evaporation, transpiration, condensation and precipitation.