Abiotic Factors Life Science 25.1

What are abiotic factors? “a” means not or without “biotic” means living These are the nonliving things in an organism’s environment Essential to the survival of organisms

Air Atmosphere-air that surrounds Earth Made up of the following: 78% Nitrogen 21% Oxygen 0.94% Argon 0.03% Carbon dioxide Tiny amounts of other elements

Carbon Dioxide and Oxygen Part of the processes of Photosynthesis and Respiration Plants take in Carbon Dioxide from the atmosphere They produce oxygen in the process of photosynthesis Most other organisms take in Oxygen from the atmosphere They produce carbon dioxide during cellular respiration

Water Essential to life on Earth All organisms need water Plants need it for photosynthesis and to avoid wilting Animals need it to avoid dehydration Most organisms are 50-95% water

Soil Mixture of several things: Mineral and rock particles Remains of dead organisms Water Air Topmost layer of Earth’s crust Supports plant growth Contains life (bacteria, fungi, insects, worms)

Sunlight Essential for photosynthesis Helps keep temperature in range that organisms can survive Responsible for weather on earth

Climate NOT WEATHER!!!! Climate refers to average weather over time Includes temperature, wind, and precipitation All are caused by the sun’s rays.

Precipitation Rain, snow, sleet, and hail Part of The Water Cycle (to be discussed soon)

Wind Results from sunlight heating air molecules Warm air rises, cool air falls The cool air coming back down to the surface causes surface winds.

Temperature Result of sunlight striking the Earth’s surface. Most organisms can survive from 0 ⁰ C to 50 ⁰ C (32 ⁰ F-120 ⁰ F) Latitude determines how much light strikes the surface At the equator, sunlight is direct. At the poles, it is spread over a wider area. (Flashlight demo) Elevation also affects temperature There are fewer air molecules higher in the atmosphere, so the temperature is lower (colder) It is typically warmer nearer the bottom of mountains than the top. Temperature vs. Elevation activity

Water Cycle Evaporation-water turns to water vapor and rises (think of boiling water on a stove) Transpiration-Plants release water into atmosphere Condensation-Water vapor droplets come together to form clouds Precipitation-Clouds get too heavy, and liquid water falls to surface Runoff-Water runs along ground, and either goes into ground or into lakes, rivers, streams, oceans, etc. Groundwater-Water that is located beneath Earth’s surface

Nitrogen Cycle Nitrogen is released into the ground through 2 processes Decaying of dead organisms Wastes (feces and urine) from organisms Nitrogen Fixation-conversion of nitrogen to usable forms (fertilizer) Plants use the fixed nitrogen to make cells Animals get the nitrogen by eating the plants Plants and animals die and decay, releasing the nitrogen back into the soil The cycle repeats.

Carbon Cycle Carbon is released to the atmosphere by: Animals breathing Burning fossil fuels (coal, oil, etc), which are the remains of dead organisms Dead and decaying organisms being decomposed Carbon enters the biotic portion of Earth by plants taking it in during photosynthesis

Cycles in Nature (Activity) Draw the 3 main cycles in Nature Water Cycle Nitrogen Cycle Carbon Cycle Use details in notes, and make sure to include all parts listed there. You may look at the pictures in the book, but they do not include all required parts. You may also look at the biology student’s cycles in the back of the room.