Page 73 - Science Course 3 (Book 1)

Mo2-L4a: How Do Organisms in an Ecosystem Interact?

Overpopulation occurs when a population becomes Predation
so large that it causes damage to the environment.
Predation is the act of one organism,
Overpopulation is temporary because when resources a predator, feeding on another organism, its prey.
eventually run out, some animals will move elsewhere,
starve, or die from disease. Predators help control the size of prey populations.
When prey populations decrease, the number of
predators usually decreases because less food is
available.
Overpopulation
Number of individuals
an environment can
sustain

Population size

Time
Symbiosis is a close, long-term relationship between
two species that usually involves an exchange of food
or energy.

Competing with Humans

Humans need some of the same biotic and abiotic
factors as other organisms, including food, living Commensalism Mutualism
space, and water.

Parasitism

A symbiotic relationship in which both organisms
benefit is mutualism.

For example, fish benefit by having tiny organisms
removed from their bodies by cleaner shrimp, and
Clearing forests, filling in wetlands, and diverting
water from lakes and streams put humans in cleaner shrimp benefit by getting food.
competition with other species for the same
resources.

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