Population — one species in an area (spec 4.1)
A population is all the organisms of one species living in an area.
Ecology is the study of how living things interact with each other and with their surroundings. To talk about it clearly, you need four key words. The first is population.
A population is all the organisms of one species living in a particular area at a particular time.
The important word is one species. A population is made of just a single kind of organism:
- all the rabbits in a meadow
- all the oak trees in a wood
- all the frogs in a pond
- all the humans in a town
Notice that a population can grow or shrink over time — more animals are born or migrate in, and others die or migrate out. But it is always counting one species only.
Exam tip. If a question asks you to define a population, the marking point is "all the organisms / members of one species in an area". Leaving out "one species" is the most common way to lose this easy mark.
- A population = all organisms of one species in an area.
- Examples: all the rabbits in a meadow; all the oak trees in a wood.
- The key phrase is 'one species'.
See the full worked example for population, community, habitat & ecosystem →