MYP Biology Interactions Between Organisms Key Definitions

When organisms require the same limited resource and not all individuals can obtain enough to survive and reproduce.

A simple, linear sequence showing how energy and nutrients pass from producers to consumers across trophic levels (e.g., producer → herbivore → carnivore → apex predator).

An interconnected network of multiple food chains that maps all feeding relationships in an ecosystem, showing species with multiple food sources and roles across trophic levels.

The reliance of organisms on other living organisms for survival and successful reproduction.

Occurs between individuals of different species that rely on the same limited resource.

Occurs between individuals of the same species.

A species with an unusually large influence on its ecosystem.

An organism that lives on or inside a host, benefits from the host’s resources, and harms the host.

A biological agent that causes disease in a host organism.

A biological interaction in which one organism (the predator) captures and consumes another organism (the prey) as a food source.

A long-term, close interaction between individuals of two different species.

A series of population changes across multiple trophic levels caused by a change in one species.

The position an organism occupies in a feeding sequence.

A living carrier that transfers a pathogen without being the primary host.