Mr. Pfeffenberger’s Science

Cycles in Nature

The Cycles of Matter �  Three cycles that moves matter among the

environment and living things �  Water cycle

�  Carbon cycle �  Nitrogen cycle

The Water Cycle

The Water Cycle �  The movement of water among oceans,

atmosphere, land, and living things.

�  Precipitation- water moving from atmosphere to land �  Ex: rain, snow, sleet, hail �  91% falls into the ocean, 9% on land renews fresh

water supply

The Water Cycle

�  Evaporation- water moving from the land to the atmosphere �  The sun’s heat causes water to change from liquid

to vapor

�  Condensation- water vapor becoming liquid again due to cool atmosphere

�  Transpiration- water moving from living things back into the atmosphere �  Ex: evaporation from leaves, perspiration from

humans

The Water Cycle �  Ground Water- precipitation that seeps into the

ground and is stored in underground caverns and porous rock �  Provides water for the soil, streams, rivers, and

oceans

�  Our water supply is not getting larger so we must protect our fresh water from pollution!!

The Water Cycle

The Carbon Cycle

The Carbon Cycle �  The movement of carbon from the environment into

living things and back again

�  Carbon is essential to all living things because it is part of our molecules.

The Carbon Cycle

�  Photosynthesis- carbon moves from the environment into living things �  Plants use carbon dioxide from the air to make

sugar �  Animals get carbon from eating plants

�  Respiration- carbon moves from living things back to the environment �  Sugar molecules are broken down to release energy

and carbon dioxide is given off when we exhale

The Carbon Cycle �  Decomposition- carbon moving from dead

organisms back to the environment �  Fungi and bacteria decompose dead organisms

�  Combustion- the process of burning fuel �  Burning fossil fuels releases carbon back into the

atmosphere

The Carbon Cycle

The Nitrogen Cycle

The Nitrogen Cycle �  The movement of nitrogen from the environment

to living things and back again. �  78% of our atmosphere is nitrogen gas

�  Nitrogen fixation- the process of bacteria changing nitrogen gas into usable nitrogen for plants �  Animals get nitrogen from eating plants

�  Other bacteria decompose dead animals and animal waste and return nitrogen to the atmosphere

The Nitrogen Cycle

Create A Comic Strip �  You and your group will be responsible for

creating a comic strip featuring an evil villain who plans to destroy an ecosystem by interrupting one of the cycles that runs in an ecosystem.

�  I will assign you a cycle of matter: �  Water Cycle �  Nitrogen Cycle

Comic Strips �  The comic strip must explain:

�  The way the cycle works �  How the villain plans on disrupting the cycle �  What effects the villain’s interruptions will have

on the cycle �  What plan your superheroes have for stopping the

interruption

�  You will be graded on: �  Having all requirements in your comic strip! �  Using color and creativity in the final product! �  20 point assignment �  All members will be graded on the final project with

a participation grade added based on their involvement in the project.