The Water Cycle — AQA GCSE Biology
The water cycle provides fresh water for organisms on land before the water drains back to the seas.
The stages
The Sun's energy drives the water cycle:
- Evaporation — energy from the Sun warms water in seas, rivers and lakes, turning it into water vapour. Water also enters the air from plants by transpiration.
- Condensation — the water vapour rises, cools and condenses to form tiny droplets, making clouds.
- Precipitation — the droplets join and fall as rain, snow or hail.
- The water collects in rivers and lakes (providing fresh water for organisms) and eventually flows back to the sea, and the cycle repeats.
Why it matters
The water cycle continually provides fresh water on land, which plants and animals need to survive. It is powered entirely by energy from the Sun.
Exam tips
- Learn the stages in order: evaporation → condensation → precipitation → drains to sea.
- The Sun provides the energy that drives the cycle.
- Transpiration from plants also adds water vapour to the air.
- The cycle provides fresh water for land organisms.