HS BIOLOGY UNIT 9: Biosphere

Terms:

• Biotic: all living factors in an ecosystem

• Abiotic: all nonliving factors in an ecosystem

• Producers: autotrophic organisms that make their own food

• Consumer: organisms that must consume other organisms for energy

• Decomposers: organisms that obtain energy from dead remains of other organisms

• Autotrophs: describes plants because they make food from sunlight

Levels of organization:

• Population: group of same species living in same area

• Community: different populations living together in an ecosystem

• Ecosystem: abiotic and biotic factors in an are

The main source of all energy in a pyramid is the sun

10% of energy is transferred only, leaving the rest of the energy to turn into heat

Symbiosis:

• Mutualism: both organisms benefit

• Commensalism: one species benefits, the other is unaffected

• Parasitism: one species benefits, the other is harmed

Succession:

• Primary succession example: new islands formed by the eruption of volcanoes

  • The first species to populate are the pioneer species

• Secondary succession example: after a forest fire

  • There was life before destruction

Carbon cycle: producers take in carbon while consumers emit carbon. Carbon is returned to the soil when organisms decompose, and returned to the atmosphere when fossil fuels are burned

Nitrogen cycle: atmospheric nitrogen must be fixed by bacteria in the soil, so plants can absorb and use it. Nitrogen returns to the soil when organisms decompose