18.3 Types of Interactions

Limiting Factors & Carrying Capacity

Limiting Factor – something that limits the size of a population Ex: Food, Water, Space

Carrying Capacity – the largest population that an environment can support.

Limiting factors influence the carrying capacity.

Competition

Competition occurs when two organisms try to use the same resources.Can be within a population or a community

Predation Prey – organism that is

killed & eaten by another

Predator – organism that kills another for food.

Predators have adaptations that help them capture their prey (i.e. speed, sharp teeth, claws).

Prey also have adaptations to protect themselves (i.e. camouflage, poison).

Symbiosis

Symbiosis is the long term association or relationship between organisms that benefits at least 1 organism.

3 Types: Mutualism, Commensalism, Parasitism

Mutualism

Symbiotic relationship in which both organisms benefit.

Example: Egyptian Plover &

the crocodile

Commensalism

Symbiotic relationship in which one organism benefits and the other is unaffected.

Example: Whale Shark &

Golden Trevallys

Parasitism

Symbiotic relationship in which one organism benefits and the other is harmed.

Example: Ant & Parasitic Fungus

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Comprehension Check

How do limiting factors affect the carrying capacity?

How are the three types of symbiosis different?

How are predation and parasitism different?