Ch 2 Review. The Water Cycle. The water cycle is the movement of water between the oceans, atmosphere, land, and living things. Stages of the Water Cycle. Evaporation – The change of a substance from a liquid to a gas, where the water is cycled back into the atmosphere.
E (Evaporation) – The change of a substance from a liquid to a gas
B (Condensation)- The change of state from a gas to a liquid
D (Groundwater) - Water that seeps into the ground & slowly flows back into soil, streams, rivers, & oceans
A (Transpiration) - The process of plants releasing large amounts of water vapor
F (Runoff) - The precipitation that falls on land that flows into streams, rivers, oceans, and lakes
C (Precipitation) - Any form of water that falls to the Earth’s Surface from the clouds
G (Water Cycle) - The movement of water between the oceans, atmosphere, land, and living things
2. ____________________ 5. ____________________
3. ____________________ 6. ____________________
__ _ _____ _____________ _
Rain, snow, sleet, & hail
The water cycle is how the Earth’s water recycles itself. Without water, there would be no life on Earth. All organisms are composed mostly of water and eventually, all the water taken in by organisms is returned to the environment.
Decomposition – The breakdown of dead materials into carbon dioxide and water
Combustion - The process of burning fossil fuel or wood
** Both have organic matter that releases carbon dioxide
into the atmosphere.
Photosynthesis– The process by which plants use carbon dioxide from the air to make sugars
Respiration - sugar molecules are broken down to release energy carbon dioxide & water
Organic – molecules that contain carbon
Inorganic - molecules that do not contain carbon
Because it allows for the exchange of nitrogen between the environment and living things. During the cycle, nitrogen is changed into a form that organisms can use. Nitrogen is needed to build proteins and DNA for new cells.
5. Describe, in detail, the importance of nitrogen fixation in the nitrogen cycle. ____________________________________________________________________________________________
It is when bacteria in the soil are able to change nitrogen gas into forms that plants can use.
Animals eat nitrogen contained in plants, which helps them make protein and new cells. When an animal dies, decomposition releases nitrogen back into the
soil that can be used again.
Match the organism to its role in the nitrogen cycle.
____ Nitrogen fixation A. Herbivores and Omnivores
____ Decomposition B. Bacteria
____ Receives nitrogen by eating plants C. Plant roots
____ Takes up nitrogen from soil D. Decomposers
*BONUS: Do the three cycles you learned about (water, carbon, and nitrogen cycles) affect each other in any way? Explain.
Each cycle is connected in many ways. Some forms of nitrogen & carbon are carried through the environment by water. Many nutrients pass from soil to plans and animals and back. Living organisms play a part in each of the cycles.
plants or eating organisms that eat plants.
decomposers breaking down remains.
Stages of primary succession
A natural disaster causes a major disturbance and destroys a community leaving only some weeds left to grow
Either the wind blows seeds or insects carry seeds allowing new weeds to appear
Small trees (such as conifers may start to grow among the weeds and continue to grow to form a forest
As older trees dies, they are replaced by different trees if the climate can support them
1. Begins in a place without any soil
2. Starts with the arrival of living things such as lichens that do not need soil to survive
Primary succession is when a small community of living things starts to live in an area that had no plants or animals. Starts with bare rock -> organisms living and dying on rock-> rock turning to soil. Secondary succession is the regrowth of the original plant community in an existing area that was destroyed by a natural disaster.
Pioneer species are the first organisms to grow in an area undergoing ecological succession. Pioneer species are important because they allow for the development of an ecosystem. For example, lichens are pioneer species and they help break down the rocks during primary succession that eventually leads to soil.
Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces
When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil
3. Simple plants like mosses and ferns can grow in the new soil
4. The soil layer thickens, and grasses, ferns, wildflowers, and other plants begin to take over
These plants die, and they add more nutrients to the soil
5. After hundreds or thousands of years, conifers start to grow into a forest.