Interactions in Communities Unit 10 L 3

One relationship between organisms is that of predator-prey. Which of the following is the best description of a predator?

• an organism that eats another organism

• an organism that participates in symbiosis

• an organism that is eaten by another organism

• an organism that benefits at the expense of another organism

Aphids can infest and damage plants. Ladybugs eat these aphids. Ladybugs often live on such plants in order to be near their food source. There is evidence of which relationships in this example?

• parasitism, mutualism, and commensalism

• parasitism, predation, and mutualism

• parasitism, predation, and commensalism

• commensalism, mutualism, and predation

Which relationship is most likely to increase the population of one species in an ecosystem without affecting the population of its associated species?

• predation

• mutualism

• parasitism

• commensalism

The graph shows the population of a group of rabbits in a restricted area studied over a period of 5 years.

Which claim might explain why the population levels off as shown in the graph?

• The resources in the area ran out.

• Predators were introduced into the area.

• The rabbits encountered a new disease.

• Competition for resources limits the rabbit population.

Which of the following is an example of commensalism?

• A bird is hunted by a cat, killed, and eaten.

• A bird eats berries and then spreads the seeds.

• A bird finds an existing hole in a tree and builds a nest in it.

• A bird finds a small shellfish on a beach, cracks its shell, and eats it.