2. I. The Water Cycle- movement of water between the oceans, atmosphere, land, and living things

4. A. Stages 1. Evaporation- sun’s heat causes water to change from liquid to vapor 2. Condensation- water vapor cools and returns to liquid state

5. 3. Precipitation- water that falls from atmosphere to land and oceans (rain, snow, sleet, hail) a. Runoff - Falls on the land and flows into streams, rivers, and lakes Types of precipitation b. Groundwater- seeps into the ground and is stored between or within rocks and slowly flows back into the soil, streams, rivers, and oceans Water cycle

6. c. Infiltration- movement of water into the ground due to gravity

7. 4. Transpiration—process by which plants release water vapor into the air through stomata.

8. B. All living organisms require water 1. Transports nutrients and waste 2. Regulates temperature 3. Eventually returned to environment

9. A. All living things contain carbon (organic molecules) II. Carbon cycle- exchange of carbon between the environment and living things Carbon cycle

10. B. Stages 1.Photosynthesis- plants use sunlight, water, and carbon dioxide from air to make oxygen and sugars 2. Respiration a. Process of breaking down sugar molecules to release energy b. Organism uses oxygen and releases carbon dioxide and water back into the environment c. Occurs in plants and animals

11. 3. Decomposition a. Breakdown of substances into simpler molecules b. Ex- fungi and bacteria decompose organic matter, carbon dioxide and water return to environment) 4. Combustion a. Process of burning a substance, such as wood or fossil fuels b. Releases carbon discovery

12. A. Living things need nitrogen to build proteins and DNA but cannot use it directly III. Nitrogen cycle- movement of nitrogen between the environment and living things Nitrogen cycle

13. B. Stages 1. Nitrogen fixation- bacteria in the soil change nitrogen gas into forms that plants can use 2. Organisms eat plants or animals that eat plants 3. Organisms die, decomposers break down remains and release a form of nitrogen into the soil that plants can use 4. Bacteria in the soil convert nitrogen to gas, which returns to atmosphere

14. IV. Other minerals needed for living cells also go through cycles discovery

15. V. Succession- the replacement of one type of community by another at a single place over a period of time (ex. - re-growth of forest after fire) succession

16. A. Primary succession- a small community starts to grow in an area where other organisms had not previously lived 1. Bare rock- no soil 2. Acids from lichens break down rocks which mix with dead lichens and form soil

17. 3. Mosses grow, insects and tiny organisms live and die bringing more nutrients to the soil 4. More soil allows ferns, then grasses and wildflowers, then shrubs and trees 5. Forests form after thousands of years

18. B. Pioneer species- a species that colonizes an uninhabited area and starts succession (ex.-lichen) Pioneer species C. Climax community 1.The final, stable community in equilibrium with the environment 2.The endpoint of succession. Climax community

19. D. Secondary succession- an original community re-grows through a series of stages 1. Begins with soil already intact 2. Ex.- after forest fire, an abandoned farming field

20. E. Biodiversity 1. The variety of species that are present in an area 2. Important to survival of communities

21. Concept Map- Cycles in Nature