AIM: What are symbiotic relationships? DN: Define a predator/prey relationship. What determines the population size of each?

Relationships could be either Cooperative competitive

Predator-Prey Relationship Predator: consumers that actively hunt other organisms Prey: the organism that the predator eats

Predator and Prey population sizes are closely linked

1. What happens if the predator population increases? Why? The prey population will decrease. If there are more predators, they will need more food to eat

2. What happens if the prey population increases? Why? The predator population will increase. There will be more food available for the predators.

3. What happens if the predator population decreases? Why? The prey population will increase. There will be less predators to eat the prey.

4. What happens if the prey population decreases? Why? The predator population will decrease. There will be less food for the predators to eat.

Symbiosis Any relationship where two species live closely together. This relationship could benefit the species or it could be detrimental to the species. Parasitism: Mutualism commensalism

Parasitism One organism feeds on the tissues or body fluids of another Host: the organisms on which a parasite feeds Parasite benefits, host is affected

Parasites Examples Fleas Ticks Malaria- plasmodium (protozoa) Tapeworm Hookworm http://www.sporcle.com/games/tallsaul/plentiful-parasites

Mutualism Both species benefit Nile Crocodile and Egyptian Plover The plover eats the food stuck in the crocodiles mouth. Crocodile gets its teeth cleaned Plover gets its nutrition

Digestive bacteria and humans “good” bacteria exists in order to help us to digest food. The bacteria stay alive. The human gets help with the process of digestion.

Oxpeckers and zebras or rhinos the oxpecker (a bird) lives on the zebra or rhino, and eats all of the bugs and parasites on the animal. The bird benefits by having a readily available source of food. The zebra or rhino benefits from having the bugs removed. when there is a danger to the zebra or the rhino, the oxpecker flies high and makes much noise in order to alert nearby animals to the impending danger (i.e. a predator).

One species benefits and the other isn’t helped or harmed Commensalism One species benefits and the other isn’t helped or harmed Remora Fish and Sharks “suckerfish- attaches itself to the bodies of sharks, and uses the shark for transportation as well as protection from its predators. It also eats up the scraps of food that are left over when the shark eats its prey. The shark is not harmed nor helped

Barnacles and Whales Barnacles do not harm the whale Barnacles benefit from moving through the water with the whale, picking up food

How are predators different from parasites How are predators different from parasites? What doe these two groups have in common? Describe the concept of mutualism. Give an example. Describe the concept of parasitism. Give an example. Describe the concept of commensalism. Give an example. Suppose an unusually severe winter killed most of the snowshoe hare population in an area of northern Canada. How would the lynx population be affected?