Population Changes – Ripple Effects in Food Webs

What's in this exercise

Answers are hidden — sign up to practise and check your work.

1. Question 1

   Multiple choice

   In the food web: grass → rabbits → foxes. If a disease kills most rabbits, what happens to foxes?

2. Question 2

   Multiple choice

   What is a 'trophic cascade'?

3. Question 3

   Multiple choice

   Wolves were reintroduced to Yellowstone National Park. This caused deer numbers to fall, which allowed riverside plants to recover. This is an example of:

4. Question 4

   True or false

   If a top predator is removed from a food web, only the species directly below it in the chain is affected.

5. Question 5

   Matching

   Match each population change to its likely effect on the food web.

More exercises in this module

• Producers, Consumers, Decomposers – Roles in an Ecosystem

• Footprint Comparison – Small Choices, Big Difference

• Keystone Species – One Species, Huge Impact

• Food Chains – Plants, Herbivores, and Carnivores

• Human Actions – Positive and Negative Effects on Ecosystems

• Human Uses of Ecosystems – Food, Water, Recreation, Materials