Unit 1

• predator: an organism that hunts and kills other organisms for food
• prey: the animal that is eaten by a predator, or the animal that is hunted
• predator-prey relationship: population numbers correspond (when one population rises/falls, the other does as well)
• symbiosis: a relationship between two organisms that live in close contact with each other
• mutualism: both species mutually benefit

  (ex. bees and flowers)
• commensalism: one benefits, the other is unaffected (ex. tree frog uses a leaf as protection)
• parasitism: one benefits at the expense of the other (ex. dogs and ticks)
• competition: results when two organisms struggle to obtain the same limiting resource
• limiting resource: any resource (biotic/abiotic) that constrains a population’s size (ex. food, water, shelter)
• interspecific competition: between diff species (harmful)
• resource partitioning: species using limited resources in diff ways/diff times to reduce competition (sharing)
• intraspecific competition: between same species (strongest survive and breed, beneficial)
• biodiversity: the variety of different species in an ecosystem, including plants and animals
• biome: a large area of the same type of ecosystem
• temperate deciduous forest: deciduous trees, moderate precipitation, warm summers, cold winters
• deciduous: lose their leaves in the winter
• tropical rain forest: largest biome, high temp, high precipitation, highest productivity, high biodiversity (ex. Africa)
• tropical grasslands (savanna): hot, dry climate, tall grasses, scattered trees, large mammals
• temperate grassland (prairie): grassland with a moderate climate, moderate rainfall, and moderate temperature (ex. North America)
• tundra (cold grassland): cold climate, little rain, grazing animals, permafrost (ex. Siberia)
• desert: hot days, cold nights, very dry, no trees, organisms evolved to conserve water and be nocturnal (ex. Nevada)
• coral reef: warm, shallow waters, high productivity, animals have limestone shells
• open ocean: deep water that sunlight cannot penetrate, saltwater
• taiga (boreal) forest: evergreen trees, snowy winters, long summers, fire-resistant plants
• kelp forest: a large area of kelp in shallow water (large algae)
• estuary/wetland: where freshwater meets the ocean
• carbon cycle: the movement of carbon between the atmosphere, oceans, and living things (long duration)
• carbon largest reservoir: the deep ocean
• nitrogen cycle: the process by which nitrogen is recycled in the environment (short duration)
• phosphorus cycle: the process by which phosphorous is cycled through ecosystems (longest duration)
• phosphorus: nutrient essential for plant growth and is found in the soil
• nitrogen largest reservoir: atmosphere
• phosphorus largest reservoir: sedimentary rock
• hydrologic (water) cycle: the continuous movement of water from the atmosphere to the earth and back (short duration)
• water largest reservoir: ocean
• fixation: nitrogen gets fixed abiotically by lighting (N2) or biotically through microbes in soil/roots
• ammonification: fixed nitrogen turns into smth plants can use

  • NH3 = ammonia, NH4+ = ammonium
  • NH3 → NH4+ by soil bacteria (waste) / decay of organic material (dead things)
• nitrification: bacteria convert ammonium to nitrites to nitrates

  NH4+ → NO2 → NO3
• assimilation: plants take in the nitrates, then animals eat the plants
• denitrification: getting nitrogen back into the atmosphere by soil bacteria converting nitrogen to nitrogen gas

  NO3 → to N2