ECOLOGY CYCLES Betsy Sanford Lost Mountain Middle School
ECOLOGY - CYCLES Betsy Sanford Lost Mountain Middle School 7 th Grade Life Science
THE WATER CYCLE • What – the recurring flow of water throughout the atmosphere and the biosphere • Who - all living things need water • all forms of water, solid (snow, sleet, hail), liquid water & gas (water vapor) • Where – throughout the biosphere and atmosphere • When – constantly cycling • Why – recycling of water for reuse in chemical reactions in living things • How - changes in temperature cause evaporation, condensation, and precipitation • precipitation collects above ground in lakes, ponds and ice flows
THE NITROGEN CYCLE • What – the recurring flow of nitrogen throughout the atmosphere and the biosphere • Who – all organisms need nitrogen, but not in gas form (the atmosphere is 78% nitrogen) • Where – needed in the soil wherever plants are growing • When – constantly cycling • Why – recycling of nitrogen for reuse in making proteins and DNA • How – nitrogen gas must be chemically changed into forms plants can use to grow • bacteria in the soil “fix” nitrogen (nitrogen fixation) • plants take nitrogen from the soil and consumers eat plants to get nitrogen
THE CARBON CYCLE • What – the exchange of carbon back and forth from the environment to living things • Who – all living things are made of carbon; carbon is part of the ocean, the air and even rocks • Where – in the atmosphere as carbon dioxide (CO 2) and in molecules such as glucose (C 6 H 12 O 6) • When – constantly cycling • Why – plants use carbon dioxide to make food and all consumers use food for energy • carbon dioxide is one of the greenhouse gases that blankets the Earth to keep it warm • without this blanket of gases, the Earth would be totally frozen • How – chemical reactions • photosynthesis and cellular respiration
- Slides: 7