Ecological Stability Warm-Up

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.

Which best explains why many kinds of plants and animals can live together in an ecosystem?

• The plants and animals are all part of a food chain and depend on each other to live.
• Plants and animals are interdependent of one another.
• One species may overpopulate, killing all plant life.
• Over population of a species results in a biodiversity.

What would most likely happen if an ecosystem no longer received sunlight?

• The number of herbivores would increase
• The number of plants would increase
• all organisms would adapt
• All living organisms would eventually die

Examples of how humans negatively affect local ecosystems are

• Building dams, deforestation (cutting down trees), adding point sources to nearby streams to allow for run-off, building roads and structures, and salting roads.
• Creating laws to prohibit fishing from local streams.
• Planting trees and other plants to attract native species.
• Removing non-native species from the environment.

What does biodiversity mean?

• Only one species in an area.
• The different amount of species in an area
• All abiotic life
• Nitrogen fixation

In this tundra food web, if grasses were removed what would happen to the sustainability of the ecosystem?

• There would be an overpopulation of arctic hares and lemmings.
• Polar bears would move to a new ecosystem
• The ecosystem would collapse because it lost its main producer
• Wildflowers would die out from the ecosystem

Globally, the leading cause of biodiversity loss is 

• invasive species
• poaching and overharvesting
• pollution
• habitat change and loss 

Why are invasive species such a problem in their new ecosystem?

• a. The new ecosystem isn�t adapted to their presence
• b. The new ecosystem is probably weaker than the native one
• c. They have mutations making them more adapted to the new ecosystem
• d. They cause mutations in the native species

What is an advantage of a biodiverse ecosystem?

• Can withstand changes in resources

• Can recover more quickly from a natural disaster

• Can withstand the immigration of a new predator

• all of the above

Humans are causing extiction in which ways?

• By over hunting animals for food or products.
• By destroying the natural habitat of species.
• By polluting the environments of the world.
• All of the above.