Biology Ecology

Population

A population is all of the organisms of one species that live in the same place at the same time

Community

A community is different species all living together at the same time

Ecosystem

An ecosystem is a distinct, self-supporting system of biotic organisms interacting with each other and with the physical abiotic environment

Biodiversity

Biodiversity is the amount of variation of species shown by organisms in an ecosystem and is a measure of both number of species and abundance of each species

Factors which can affect biodiversity (abiotic)

• Climate - Temperature, Rain, Sunlight

• Land - nutrients

• Variety - allows evolution, less impact from disease, attracts more species

Factors which can affect biodiversity (biotic)

• Reproduction

• Predators - may only target one type of species

• Humans - deforestation, poaching

Producers in a food chain

Producers are trophic level 1. Use photosynthesis to produce their own food using energy from the sun. All energy from the food chain comes from them. (autotroph)

Primary Consumers in a food chain

Primary consumers are trophic level 2. First organism in food chain that consume their energy from other organisms (heterotroph)

Secondary Consumers in a food chain (from now on the cycle repeats for every trophic level)

Secondary consumers are trophic level 3. Consumer their energy from other animals (heterotroph)

Why is only 10 % of energy transferred from one trophic level to the next?

Energy is loss at every level in a food chain, by heat energy or dead remains and faeces

What are decomposers?

Decomposers are organisms that consume their energy from dead matter (saprotrophs)

Biomass formula

Number x mass