Biology: 4A Ecology and Food Chain

Ecology

Study of interactions among living things and their environment.

Biotic factors

Living components that influence an ecosystem

Abiotic factors

Non-living components of an environment, such as temperature, humidity, salinity.

Population

a group of organisms of the same species living in the same place at the same time

Community

includes all of the populations living in the same area at the same time

Ecosystem

The combination of all the living organisms (biotic factors) and non-living conditions (abiotic factors) in an environment

Habitat

The place where an organism lives

Consumer

An organism that eats other organisms

Where does all energy originally come from?

The sun

Producer

An organism that makes its own food

What do producers do?

Convert light energy from the sun into chemical energy stored in their tissues.

Plants that photosynthesise supply energy for the ecosystem.

Food Chain

A series of steps in which organisms transfer energy by eating and being eaten

Decomposer

An organism that breaks down wastes and dead organisms

Bacteria and Fungi get their energy through this.

Trophic Level

level occupied by an organism within a food chain or food web

Who is the first trophic level?

The producer

Who is the second trophic level and what do they do?

primary consumers and they eat producers, transferring energy into their tissues.

Who is the third trophic level and what do they do?

Secondary consumers and they eat primary consumers, transferring energy into their tissues.

Who is the fourth trophic level and what do they do?

Tertiary consumers and they eat secondary consumers, transferring energy into their tissues.

Food Web

A diagram showing a series of interconnecting feeding relationships and food chains

What do food webs show?

 interdependence - how the change in one population can affect others within the food web

Carnivore

An animal that only eats other animals

Omnivore

An animal that eats both plants and animals

Herbivore

An animal that only eats plants

What are quadrats?

square frames made of wood or wire

What are quadrats used for?

Plants species are commonly studied using quadrats to estimate the abundance

List the ways that quadrats count abundance

Recording…

• the number of individuals of a single species, e.g. buttercups

• species richness: the number of different species present

• percentage cover: the approximate percentage of the quadrat area in which an individual species is found