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Aim: How does competition affect organisms in nature?. Do Now: List three things you compete for in your life. II. Predator-Prey Relationships. A. Predators help control the size of the prey populations
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Aim:How does competition affect organisms in nature? Do Now: List three things you compete for in your life.
II. Predator-Prey Relationships A. Predators help control the size of the prey populations 1. Prey populations are kept below their carrying capacity (The max. number an ecosystem can support). Example: NYS Deer.
II. Predator-Prey Relationships B. Population explosions are common when prey populations are moved into areas that don’t have natural predators. Ex - Rabbits in Australia • 1859 - one dozen rabbits were introduced • 1865 - 20,000 rabbits were shot • 1887 - 20,000,000 rabbits were shot
II. Predator-Prey Relationships C. Prey populations control the size of the predator populations 1. When a predator has one type of food, it depends on how many prey there are. ex. Lynx and Snowshoe hairs
II. Predator-Prey Relationships D. Neither predator nor prey influences the other’s population size. 1. This occurs when a predator relies on many different prey species for food. Example: Humans
Objective: Population Size Do Now: • Take out your HW to be checked. • Why is the interaction on the next slide taking place, and predict what will happen next.
Zebra Mussels http://www.unitedstreaming.com/personalized/myContent.cfm?rand=E1D94B3A-F20F-7604-EC09DCC69EBE146B
III. Food Chains – show what things eat. • Parts of the food chain: • Producers – make their own food. • Herbivores – eat plants only • Carnivores –eat animals only • Omnivore – eat plants or animals • Decomposers – break down dead organisms back to soil.
III. Food Chain B. Food Web – shows overlapping food chain.