Unit 2 Lesson 3: Patterns of Interaction

Unit 2 Lesson 3: Patterns of Interaction

Open Ended

Besides food, what else do we depend on animals for?

Ecosystems have many interactions between organisms.

• Feeding relationships are some of the most important.

• Everything needs energy and nutrients from food.

Some animals have very diverse diets.

• This means that they are able to feed on a wide range of items.

Open Ended

Give at least one advantage to being able to eat a wide variety of things.

Some animals are "specialists" that feed only on specific things.

• For example, eucalyptus makes up nearly all of a koala's diet.

• Eucalyptus leaves are rather low in nutrients and contain many toxins.

Open Ended

What would be an ADVANTAGE to eating something that is toxic to most organisms?

Predator-Prey Relationship

• In this type of relationship, one animal is eaten by another.

• The population of the predator is limited by the availability of its prey, and vice-versa.

Predatory interactions occur in all ecosystems.

• Not all "predators" are obvious...

Herbivores feed only on plants, but animals take advantage of different parts of plants.

This decreases competition.

Populations of predators and their prey impact one another.

This is true of animals AND plants!

Multiple Choice

Analyze the graph. At which point are BOTH the moose and wolf populations increasing?

• Point A

• Point B

• Point C

• None of these.

Multiple Choice

Analyze the graph. At which point is the population of moose decreasing while the population of wolves is increasing?

• Point A

• Point B

• Point C

• None of these.

Multiple Choice

Which statement explains why the wolf and moose populations rise and fall opposite of one another, rather than rise and fall at the same time?

• When the moose population is low, wolves tend to have larger litters of pups.

• As the moose population increases they eat more plants, which causes the wolves to lose habitat.

• It takes time for a population of wolves to increase once the population of their prey increases.

• After a wolf population decreases, it takes a while for more moose to migrate to the area.

Multiple Choice

For the population of wolves and moose to remain stable in this ecosystem...

• the wolf and moose populations must remain equal.

• there must be more wolves than moose.

• there must be more moose than wolves.

• a new predator for the moose must move into the area.

Multiple Choice

Having far more prey available than predators can feed on is always beneficial for the ecosystem.

• True

• False