Mutalism/Competition

What differentiates macroparasites from microparasites?

Macroparasites are larger species like arthropods and tape worms; microparasites are microscopic, such as bacteria and viruses.

What is an obligate intracellular parasite?

A virus that cannot replicate or reproduce outside of a host cell.

What is unusual about the number of parasites a single organism can host?

It's unusual for any single organism to host all potential parasite species.

What are ectoparasites?

Parasites that live on the outer body surface of the host.

What are endoparasites?

Parasites that live inside their hosts, within cells, tissues, or in the alimentary canal.

What is a primary host?

The host where the parasite reaches its adult stage and reproduces sexually.

What is a secondary host?

The host where the parasite develops or undergoes a life cycle phase but does not reach sexual maturity.

Why do endoparasites produce enormous numbers of offspring?

To compensate for the very low probability that young will successfully disperse to new hosts.

How do some parasites manipulate their primary hosts?

By altering their behavior in ways that promote the completion of their life cycle.

What are the two types of host defenses against parasites?

Physical defenses and immune system responses.

What is an example of a physical defense against parasites?

Tough skins or shells.

What role do specialized immune cells play in host defenses?

They identify, engulf, and destroy microparasites.

What do encapsulation defenses do?,

Blood forms capsules around smaller parasites, more common in insects.

What pressure do parasites face regarding virulence?

They are under pressure not to be so virulent as to kill their host too quickly.

What is intraspecific competition?

Competition among individuals of the same species.

What is interspecific competition?

Competition between individuals of different species.

Name one type of consumptive competition.

Two mice species competing for food.

What are Schoener's five types of competition?

1. Intraspecific - same species competition. 2. Interspecific - different species competition. 3. Consummative - competition for resources. 4. Preemptive - occupying space. 5. Chemical (allelopathy) - using chemicals to inhibit growth.

What defines preemptive competition?

One organism occupies space, preventing another from having it.

What is allelopathy?

Chemical warfare between competitors in chemical competition.

What is the role of resources in competition?

Resources are consumed by individuals to survive and support population growth.

What are conditions in ecological terms?

Factors that affect growth and reproduction but are not consumed.

What dictates the outcome of competition according to Liebig's law of the minimum?

The availability of the scarcest resource.

How does niche overlap affect competition intensity?

Greater overlap increases the intensity of competition.

What is asymmetric competition?

When the effects of competing species on each other are not equal.

What is amensalism?

The most extreme form of asymmetric competition, where one species is negatively affected and the other is not affected at all.

What differentiates a fundamental niche from a realized niche?

Fundamental niche occurs in absence of competition; realized niche exists with competition.

What is trophic mutualism?

Mutualism that helps in obtaining energy and nutrients.

What does defensive mutualism provide?

Shelter and defense against enemies.

What is dispersive mutualism?

Mutualism that helps in dispersing individuals, seeds, or pollen.