Science Lesson: The Water Cycle

Introduction

• Video aims to describe the stages of the water cycle.
• Previous content covered: Water as an abiotic factor influencing ecosystems.

Key Concepts

• Abiotic Factor: Non-living elements in an ecosystem.
• Water Cycle in Ecosystems: Continuous movement of water around the Earth and its ecosystems.

Stages of the Water Cycle

1. Evaporation

• Most water is in the oceans (saltwater).
• Evaporation: Sun's energy causes ocean water to evaporate into the air as water vapor.

2. Condensation

• Water vapor rises, cools, and condenses to form clouds.

3. Precipitation

• Water falls to the ground as precipitation: rain, snow, hail, sleet.
• All precipitation is fresh water (no salt).

4. Water on the Ground

• Evaporation: Some water returns to the atmosphere.
• Aquifers: Some water infiltrates into the ground through rocks.
• Rivers and Streams: Much water forms waterways, eventually returning to the sea.

Role of Living Organisms

Plants

• Absorb water through roots.
• Water travels up to the leaves via xylem.
• Transpiration: Water vapor exits through leaf stomata.

Animals

• Obtain water by drinking and eating.
• Release water through urine, feces, and exhalation.

Additional Resources

• Practice questions available in the revision workbook linked at the end of the video.