Keystone Species

A species that plays a critical role in the health, maintenance, growth, or definition of an ecosystem.

• keystone

• invasive

• engineer

• predator

Why are bees considered a keystone species?

• The honey they make supports the bear population

• They pollinate flowers that produce fruit which supports the ecosystem

• They sting when threatened

• They live in hives

Why are some sharks considered a keystone species?

• Because they are a top predator

• They scare off smaller fish that may overgraze an area of sea grass

• They are tertiary consumers

• They are cartilaginous

Which one of the following keystone examples is a keystone predator found in the tidal pools of northwestern North America and was the species that launched Robert Paine’s keystone species concept?

• starfish

• sea otters

• beavers

• wolves

• elephants

Which of the following would be the most likely effect, if there were a sudden increase in the cricket population?

• There would be a decrease in the small bird population.

• There would be a decrease in the grass/flowers population.

• There would be a decrease in the mice population.

• There would be an increase in the grass/flowers population.

In this food chain, what will happen if the frogs become extinct?

• The snakes will increase.
• The grasshoppers will decrease.
• The eagles will remain the same.
• The grasshoppers will increase.

A food chain shows the transfer of ___ from one organism to another. 

• matter
• consumers
• energy
• habitat

A keystone species fills a unique ecological niche and therefore carries unique functions in an ecosystem

• True

• False

Why is biodiversity important?

• Species diversity ensures natural sustainability

• Species are more resistant to disease and disturbances

• Creates a functional and healthy ecosystem

• Purifies our air and water supplies

• All of the above

Would removing wolves from Yellowstone National Park affect the balance of the ecosystem?

• No, they are a threat to wild animals and livestock

• Yes, the population of animals they prey on would increase causing too much competition for food