Chapter 4.2: Niches and Community Interactions

Why can't 2 organisms compete if they live in different habitats?

2 organisms can't compete if they're in different habitats because they would compete for different things.

How is a niche like a profession?

A niche is like a profession because it's about what you do and where you live.

What is the difference between a predator and a parasite?

A parasite lives on or inside the organism , but a predator kills and consumes its prey.

What are the 3 major types of symbiosis?

Biologists recognize 3 main classes of symbiotic relationships in nature: mutualism, parasitism, and commensalism.

How does competition shape communities?

By causing species to divide resources, competition helps determine the number and kinds of species in a community and the niche each species occupies.

Does each warbler have its own niche?

Each warbler has its own niche, but live in the same habitat.

How might dramatic decrease in vegetation lead to a decrease in prey species?

If there is less vegetation, herbivores won't be able to eat anything, so they won't have enough energy to escape from predators.

Bacteria living in a cow's stomach help the cow break down the cellulose in grass, gaining nutrients in the process. Is this an example of commensalism or mutualism?

It would be commensalism because the cow is getting nutrients from the grass, but the grass is not helped or harmed.

How do predation and herbivory shape communities?

Predators can affect the size of prey populations in a community and determine the places prey can live and feed. Herbivores can affect both the size and distribution of plant populations in a community and determine the places that certain plants can survive and grow.

mutualism

a kind of relationship in which both organisms benefit

parasitism

a relationship in which 1 organism lives inside or on another organism and harms it

commensalism

a relationship in which benefits and the other is neither helped or harmed

keystone

a single species whose population changes can cause dramatic changes in the structure of a community

herbivory

an interaction in which 1 animal (the herbivore) feeds on producers (such as plants)

predation

an interaction in which 1 animal (the predator) captures and feeds on another animal (the prey)

symbiosis

any relationship in which 2 species live closely together

competition

occurs when organisms attempt to use the same limited ecological resource in the same place at the same time

resource

refers to any necessity of life, such as water, nutrients, light, food, or space

competitive exclusion principle

states that no 2 species can occupy exactly the same niche in exactly the same habitat at exactly the same time

tolerance

the ability to survive and reproduce under a range of environmental circumstances

habitat

the general place where an organism lives

niche

the range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce