Transcript Cycles in Nature

Cycles in Nature
7th Grade Science
Environmental Science
Water Cycle
Water Cycle
-Movement of water between oceans, atmosphere,
land & living things
-Parts:
1. Evaporation – liquid to vapor
2. Condensation – vapor to liquid
3. Precipitation – liquid falls from atmosphere
4. Transpiration – evaporation of water from
leaves
-Same water has been here for billions of years! You
drink the same water that the dinosaurs drank!
Carbon Cycle
-Exchange of carbon between environment & living
things.
-Plants use CO2 from air to make food.
-Animals get carbon by eating plants.
-Carbon returns to environment through respiration,
decomposition, or combustion.
-What is respiration, decomposition & combustion?
Carbon Cycle
Nitrogen Cycle
-Movement of nitrogen between environment & living
things.
-About 78% of air is nitrogen gas.
-Most organisms cannot use nitrogen gas directly.
-Has to be “fixed” into usable form by bacteria in soil.
-Plants take usable nitrogen into roots, animals eat
plants.
Nitrogen Cycle