05 Ecological Relationships Free Online FlashCards

What do +, −, and 0 mean in ecological interaction notation?

A plus sign means a benefit, a minus sign means harm, and zero means no significant effect on a species.

What is competition, and what are its typical effects?

Competition occurs when organisms use the same limited resource. It is generally −/− because each has less access to that resource.

What defines predation, and how does it affect predator and prey?

In predation, a predator captures and eats prey. The predator benefits and the prey is harmed (+/−).

What is herbivory, and what happens to the organisms involved?

Herbivory is feeding on plants or algae. The herbivore gains food, while the plant or alga is harmed, though it may survive.

What is symbiosis?

Symbiosis is a close, sustained interaction between organisms of different species.

What does a food chain represent?

A food chain shows one pathway by which energy and nutrients pass as organisms eat one another.

What is a trophic level?

A trophic level is an organism's feeding position. Producers form the base; herbivores are primary consumers, and predators that eat consumers occupy higher levels.

How can species reduce competition through resource partitioning?

Resource partitioning reduces competition when species use different foods, areas, or feeding times.

What is mutualism? Give the lichen example.

Mutualism is a +/+ relationship in which both species benefit. In lichens, a fungus provides structure and protection while photosynthetic partners provide sugars.

What is commensalism?

Commensalism is a +/0 relationship: one species benefits while the other is not significantly affected, as when a bird nests in a tree.

What happens to parasite and host in parasitism?

In parasitism, the parasite benefits by living in or on a host, which is harmed. A tapeworm obtains nutrients from its host.

What does a food web show that a single food chain does not?

A food web connects many food chains, representing the varied feeding relationships in a community.