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 0⁰C to 50⁰C (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.