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ORGANISMS AND THEIR ENVIRONMENT. The Biosphere. = any part of the earth which supports living things Includes land, water, and soil Consists of biotic (living) things and abiotic (non-living) things Biotic factors : plants, other animals, fungi, bacteria, etc.
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The Biosphere = any part of the earth which supports living things • Includes land, water, and soil • Consists of biotic (living) things and abiotic (non-living) things • Biotic factors: plants, other animals, fungi, bacteria, etc. • Abiotic factors: air temperature, length of day and night, soil quality, amount of rainfall, etc.
Ecological Levels of Organization • Individual Organism • Each organism has a habitat where it lives out its life • Example: a lawn, a pond, a grove of pine trees • Size of habitat varies for different species • Several different species can share a habitat • Example: a pond contains many different species of fish, plus bugs, plants, bacteria, etc. • Each species occupies a niche in the habitat—how it lives, what it eats, etc. • No 2 species can occupy the same niche in the same habitat
Population = group of organisms, all the same species, living in a particular area at the same time • Example: we can talk about the elk population in Rocky Mountain National Park • Community = several interacting populations living together in an area • Example: the forest community in RMNP, which includes elk, deer, bears, many different plants, etc. • Ecosystem = community and the abiotic factors • example: the forest community and the climate, temperature, pollution, wind, etc. • Biosphere
Symbiosis = a close, permanent relationship between 2 different species 3 kinds: mutualism, commensalism and parasitism • Mutualism = symbiotic relationship in which both species benefit • Example: lichen, which is a combination of an algae and a fungus • fungus is “fed” by food made by the algae, which can do photosynthesis • Algae benefits because the fungus is better able to find and soak up water
Example: cleaner wrasse lives on other fish • Fish gets cleaned by the wrasse • Wrasse gets food from whatever it can scavenge • Example: E. coli which lives in your gut • E. coli breaks down your food for you • E. coli gets a lot of nutrients from your food
Commensalism = one species benefits, the other is neither helped nor harmed • Example: birds that ride on cows’ backs • Birds get food to eat when the cow walks and stirs up insects • Cow doesn’t care—it doesn’t get anything back from the bird at all
Parasitism = parasite harms, but does not kill, the host; parasite benefits, host is harmed • Example: tapeworm which lives in intestines of animals • Tapeworm eats your food and harms you • Example: brown-headed cowbird is a “nest parasite” • Lays eggs in nests of songbirds so the other birds will raise their young for them