Keystone Species – One Species, Huge Impact

What's in this exercise

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

1. Question 1

   Multiple choice

   What is a keystone species?

2. Question 2

   Multiple choice

   Sea otters eat sea urchins. Sea urchins eat kelp. If sea otters disappeared, what would most likely happen?

3. Question 3

   Multiple choice

   Bees are considered a keystone species because:

4. Question 4

   True or false

   Removing a single species from an ecosystem can never cause other species to go extinct.

5. Question 5

   Matching

   Match each keystone species to the consequence of its removal.

More exercises in this module

• Producers, Consumers, Decomposers – Roles in an Ecosystem

• Footprint Comparison – Small Choices, Big Difference

• Food Chains – Plants, Herbivores, and Carnivores

• Population Changes – Ripple Effects in Food Webs

• Human Actions – Positive and Negative Effects on Ecosystems

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