Unit 19 Environmental Interdependence Concise Notes
Unit 19 Flashcards:
Ecology
-the study of the relationships between a living organisms and its environment
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The Hierarchy of Life
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Organism
-an individual living thing, like a mouse
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Species
-a group of very similar organisms that can interbreed and produce fertile offspring
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Population
-organisms of the same species that live in the same place at the same time
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Community
-all of the different populations of species that live in the same place at the same time
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Ecosystem
-a community of living organisms and their nonliving surroundings
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Habitat
-the place where an organism live, like a grassland
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Niche
-the role that a species plays in an ecosystem
-the mouse lives in a grassland, builds its nest below ground, eats seeds and insects, and provides food for snakes
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Biotic Factors
-living parts of an ecosystem
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Abiotic Factors
-nonliving parts of an ecosystem
-soil, rocks, water, atmospheric gases, pH, temp., pollution
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Ecological Relationships
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Autotrophs
(producers)
-organisms that make their own food
-plants, algae, some bacteria
-have chloroplasts*
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Heterotrophs
(consumers)
-organisms that must consume other organisms to get nutrients and energy - cannot make its own food
-herbivores, omnivores, decomposers
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Saprotrophs
(decomposers)
organisms that break down dead organisms to get the energy they need
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Relationships
5 Main Kinds - plant-herbivore; predator-prey; competition; cooperation; symbiotic relationships
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Plant-Herbivore
-plant adaptations
thorns and poisons to keep herbivores from eating them herbivore adaptations- longer digestion cycles than carnivores; cows have large molar teeth in order to breakdown cellulose in grasses; cows have special bacteria in their stomachs to aid in digesting the grass |
Predator-Prey
-one organism catches and feeds off of another organism
-predator adaptations
hawk – keen eyesight, sharp beak and talons mountain lion – camouflage coloration, teeth designed to tear flesh
-prey adaptations
poisonous frogs have bright coloration
mimic coloration of poisonous prey
-king snake mimics coloration of coral snake
-some insects have shapes to help blend in with environment
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Competition
-organisms use the same resources – light, food, water, space
-kudzu covers trees, preventing them from getting light
competitive exclusion – the extinction of one species in an area because another was more successful
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Cooperation
-Populations work together;
-Honeybees divide labor
-Wolf packs hunt together
-reindeer herd together for protection against predators
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Symbiotic Relationships
-Relationships - “living together” – 3 kinds
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Parasitism
-one organism (parasite) benefits, the other organism (host) is harmed
-heartworms feed off of and weaken but do not kill the dog
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Mutualism
-both species benefit
flowers make nectar for insects to eat; insects help flowers reproduce by carrying pollen to other flowers
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Commensalism
-one species benefits, the other is not helped or harmed
a barnacle attaches to whales which helps it get food; the whale is not helped or harmed by the barnacle
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Flow of Energy in Ecosystems
-Energy and matter (nutrients) flow constantly through an ecosystems
-Sun – ultimate energy source for life on earth
-energy flows in only one direction, while nutrients can be recycled by decomposers
-energy flows from producer, to primary consumer, to secondary consumer...
-much of the energy in an ecosystem is converted to heat, which cannot be reused by organisms
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Producers (autotrophs)
-get energy from the sun or from chemicals
-Photosynthesis – process that uses the sun's energy to make food from inorganic materials (plants et.al.)
the sun's energy is stored in the chemical bonds of carbohydrates
-Chemosynthesis – using chemicals to make food
-All organisms use cellular respiration to acquire energy
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Consumers (heterotrophs)
-get their energy by eating producers or other consumers
-cellular respiration – process breaks down carbohydrates to release energy
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Types of Consumers
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Primary Consumer
-consumes producers
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Secondary Consumer
-consumes a primary consumer
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Tertiary Consumers
-consumes a secondary consumer
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Herbivores
– eat only plants
have cutting teeth in the front and flat teeth in the back for chewing
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Carnivores
– eat only animals
sharp canine teeth for tearing and ripping flesh
Omnivore
-eat both plants and animals
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Decomposers (saprotrophs)
– break down dead organisms for food
-fungi and bacteria
-fungi break down the dead tissue of a wolf who has died
-use the lowest energy level
-do not recycle energy or matter
-producers benefit most from decomposers
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The Flow of Energy in an Ecosystem
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Food Chains
-the simplest explanation for the flow of energy in an ecosystem
doesn't fully show the flow of energy – relationships usually more complex
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Food Webs
-interactions of a network of food chains – more complex
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Trophic Levels
-how many times energy has been transferred
-First Trophic Level - producers
-Second, Third… - made of consumers
-Organisms in each level obtain energy from the organisms in the level below them
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Energy Pyramid
– show how energy is transferred to each trophic level
-Only about 10% of the energy at each level is transferred to the next higher level
-The rest of the energy is used by the organism for metabolism, respiration, movement, and some is lost to the environment as heat
-The higher up an organism is on the energy pyramid, the less energy is available for that organism
-A Tertiary consumer has less energy available to it than a secondary consumer
-Decomposers are always the lowest energy level in any food chain or food web
-Producers (at the bottom of the energy pyramid) have the most energy available
-Top Consumer (Top Predator) – the organism at the top of a food chain or energy pyramid
----usually a large carnivore
----usually has no natural enemies
----lower energy level
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Biomass Pyramid
– shows the amount of organic material in a given trophic level
Biomass - the mass of dry (no water) organic matter in an organism
-Similar to an energy pyramid, biomass from producers is passed on to first level consumers
-Biomass from first level consumers is passed on to second level consumers
-biomass decreases from one trophic level to another as you go up the pyramid
-top of the pyramid has the fewest organisms - lots of mice, few owls
-Producers make the base of the pyramid and have the greatest biomass
-The top trophic level has the least biomass
-Carbon, oxygen, nitrogen, and water are all recycled
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