Organisms and their environment

Question 1

Population

Answer 1

a group of organisms of one species, living in the same area at the same time.

Question 2

Ecosystem

Answer 2

A unit containing all of the organisms and their environment, interacting together, in a given area eg: decomposing log or a lake

Question 3

Community

Answer 3

All of the populations of different species in an ecosystem

Question 4

Food chain

Answer 4

A diagram showing the flow on energy from one organism to another, starting from a producer

Question 5

Food web

Answer 5

A network of interconnected food chains

Question 6

Energy loses

Answer 6

When an orgasm uses food for respiration some of the energy released from their food is lost as heat energy to the environment

• An organism does not consume the entire of the prey, therefore not all energy is transferred
• Some energy is gone out with faeces

Question 7

Trophic level

Answer 7

The position of an organism in a food chain, food web or pyramid of biomass or number

Question 8

Decomposers

Answer 8

An organism which gets its energy from a dead or waste organic matter

Question 9

Nitrogen fixation

Answer 9

Changing nitrogen gas into a more reactive gas

Question 10

Methods nitrogen fixation can occur

Answer 10

Lightning – Combines some O2 to N2 to produce nitrogen oxides which dissolves in rain and enters soil as nitrates

Artificial fertilisers – Chemically combines H2 and N2 to form ammonia