Populations.

Habitat - organism lives.

Population - all the organisms of one species in a habitat at the same time.

Community - all populations of all the species in a habitat at the same time.

Ecosystem - all the organisms and abiotic conditions in a particular area at the same time.

Abiotic - non living features of a habitat.

Biotic - living features.

Niche - the role of a species within a habitat.

Adaptation - a feature that members of the species has that increases their chance of survival and reproduction.

This method allows the total population size to be calculated. However its accuracy relies on certain assumptions being true:

• the marking doesn't effect the animals abilty to survive + reproduce and the marking is still visible
• the marked organisms have time to mix back in with their population
• there is no major change in population due to births/deaths/migration

FIELDWORK + ETHICAL ISSUES!

• the captured organisms are not stressed causing harm or injury - should be released straight after marking
• soil erosion due to people being in the ecosystem
• the experimental people should make smallest effect on pop. possible