Download Student Exploration Sheet: Growing Plants

STUDY GUIDE – GEOCHEMICAL CYCLES
Water (Hydrologic) Cycle constant movement of water from Earth to the atmosphere and back to Earth
Condensation - water vapor (a gas) changes to liquid water.
Ex: clouds in the sky, water drops form on outside of a glass of icy water are condensed water
Evaporation - liquid water becomes water vapor (a gas).
Ex: water in a puddle drying up and becoming water vapor in the air
Precipitation - water that falls from clouds in the sky
Ex. Snow, rain, hail, sleet
Transpiration - the process by which water evaporates through tiny holes in a plant’s leaves
***Humans effect the water cycle by polluting groundwater, lakes, oceans, and the atmosphere***
***Burning fossil fuels creates acid rain****
Renewable resource - a resource that can be replaced easily or cannot be used up
Ex. Water, wind, sunlight
Non-renewable resource – a resource that can be used up and is not easily replaced.
Ex. Gas, oil, wood, coal
Carbon Cycle
Living organisms are made up of organic molecules that contain carbon (C)
Photosynthesis = plants use carbon dioxide to make sugars
Cellular Respiration = plants and animals use oxygen and release energy and carbon dioxide from food
Combustion = a substance burns and releases carbon dioxide
Ex. Burning fossil fuels (oil or coal)
Decomposition = organic matter is broken into simpler molecules by fungi or bacteria (returns C to soil)
*** Humans affect the C cycle by burning fossil fuels and cutting down trees****
Deforestation: cutting down of trees
Global Warming: “Greenhouse Effect” carbon dioxide (CO2) builds up in the atmosphere and traps the sun’s heat.
Driving hybrid cars (electric and gas) can help cut down on CO2 levels
Nitrogen Cycle All living things need N to build new cells, bacteria are very important
Nitrogen Fixation: bacteria turn N2 in the soil into a form that is used by plants
Assimilation: organisms obtain nitrogen by eating plants
Denitrification: bacteria converts nitrogen in the soil into N2 that enters the atmosphere
Decomposition: dead organisms are broken down by fungi and bacteria to return N to the soil
Lightning: lightning converts nitrogen in the air
Legumes: plants that contain bacteria in their root nodules that fix nitrogen. Ex. Beans
Ozone Layer: a layer of “heavy” oxygen (O3) molecules in the atmosphere. It blocks the sun’s harmful Ultraviolet (UV)
rays from reaching the Earth’s surface. Helps prevent skin cancer.
The ozone layer is created when O2 molecules are struck by UV rays and turned into O3 molecules.
CFC’s wear away at the ozone layer
***Humans effect the ozone layer by releasing chloroflourocarbons (CFC’s produced by aerosol spray cans)***