1. Repeating, Connected, Predictable
Cycles
Repeating, Connected, Predictable

2. Where have you heard the word cycle before?
Water cycle?
Motorcycle?
Bicycle?
Wash cycle?
Recycle?

3. What do you think that a cycle is?
A cycle is a predictable repeating pattern. Here are some other cycles that you may not have thought of:
Lunar cycle
Seasons
Day and night
Life cycle of animals and plants
Food chains/webs
Carbon cycle
Nitrogen cycle

4. The water cycle

5. The process of water movement from the ground to the sky and then back to the ground is called the Water Cycle.

6. The Lunar Cycle
Day
Night

7. We see the moon differently each night
We see the moon differently each night. The differences are called phases.

8. Another important cycle is the food web or food chain.
The food web begins with the sun.
The sun gives energy to plants
The plants feed consumers
The consumers are eaten by other consumers
Animals and plants die and decomposers break the plants and animals down into nutrients that help new plants to grow.
The cycle repeats

9. sun

10. The arrows show the direction of energy flow.

11. Food chains and food webs show the flow of energy through an ecosystem
Food chains and food webs show the flow of energy through an ecosystem. Food chains are linear depictions of energy flow, while food webs show the multiple interactions among the different types of organisms. Food webs are generally a more realistic portrayal of the energy flow in the system. After all, most organisms eat more than one type of food and can be eaten by more than one type of predator.

12. Life Cycles

13. Photosynthesis is a cycle

15. The Nitrogen Cycle
1. Organic wastes (from plants and animals) add nitrogen to the soil.
2. Bacteria in the soil convert the nitrogen into forms plants can use.
3. Plants use nitrogen in the soil to grow, develop, and produce seeds.
4. Plants are eaten by animals and people. The organic waste (which contains nitrogen) is returned to the soil again.

17. The Carbon Cycle

19. Seasons come in a cycle Winter always comes before
spring. Spring always comes before
summer. Summer always comes before
fall. Fall always comes before
winter

20. Cycles are everywhere. We see cycles in:
Living things
The Earth
The sky
The water