Unit 19 Study Notes and Links

Unit 19 Environmental Interdependence Concise Notes

Unit 19 Flashcards:

Ecology -the study of the relationships between a living organisms and its environment
The Hierarchy of Life
Organism -an individual living thing, like a mouse	Species -a group of very similar organisms that can interbreed and produce fertile offspring	Population -organisms of the same species that live in the same place at the same time	Community -all of the different populations of species that live in the same place at the same time	Ecosystem -a community of living organisms and their nonliving surroundings
Habitat -the place where an organism live, like a grassland	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		Biotic Factors -living parts of an ecosystem	Abiotic Factors -nonliving parts of an ecosystem -soil, rocks, water, atmospheric gases, pH, temp., pollution
Ecological Relationships
Autotrophs (producers) -organisms that make their own food -plants, algae, some bacteria -have chloroplasts*	Heterotrophs (consumers) -organisms that must consume other organisms to get nutrients and energy - cannot make its own food -herbivores, omnivores, decomposers		Saprotrophs (decomposers) organisms that break down dead organisms to get the energy they need
Relationships 5 Main Kinds - plant-herbivore; predator-prey; competition; cooperation; symbiotic relationships
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		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	Cooperation -Populations work together; -Honeybees divide labor -Wolf packs hunt together -reindeer herd together for protection against predators

Symbiotic Relationships -Relationships - “living together” – 3 kinds
Parasitism -one organism (parasite) benefits, the other organism (host) is harmed -heartworms feed off of and weaken but do not kill the dog	Mutualism -both species benefit flowers make nectar for insects to eat; insects help flowers reproduce by carrying pollen to other flowers	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
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
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		Consumers (heterotrophs) -get their energy by eating producers or other consumers -cellular respiration – process breaks down carbohydrates to release energy
Types of Consumers
Primary Consumer -consumes producers	Secondary Consumer -consumes a primary consumer	Tertiary Consumers -consumes a secondary consumer
Herbivores – eat only plants have cutting teeth in the front and flat teeth in the back for chewing	Carnivores – eat only animals sharp canine teeth for tearing and ripping flesh Omnivore -eat both plants and animals	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
The Flow of Energy in an Ecosystem
producers get energy from the sun and store it in chemical bonds consumers get energy and nutrients from producers decomposers get energy and nutrients from producers and consumers who die decomposers break down nutrients into inorganic form that can be used again by producers
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	Food Webs -interactions of a network of food chains – more complex	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

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

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