Unit 7 Pre-Quiz

The best description of an organism's niche is its:

• ideal climate

• source of food

• role in the food chain

• maximum population

How do species that fill the same niche as each other survive in ecosystems?

• One will eliminate the others

• This does not happen in ecosystems

• They adapt to fill slightly different niches

• The ecosystem will adapt to support them

Which of the following is true of an apex predator?

• They only eat producers

• They have no natural enemies in the ecosystem

• They are the only ones that can alter a food chain

• They need a larger habitat than most other animals

All of the following are apex predators EXCEPT

• some cod

• polar bears

• killer whales

• phytoplankton

Competition only occurs between members of the same species.

• True

• False

Symbiotic relationships are beneficial to ecosystems because they

• always involve the sharing of food sources

• allow multiple species to survive in the same ecosystem

• allow predator-prey relationships to balance each other out

• are a standard part of marine ecosystems but not of those on land

Which of the following populations are at risk of desiccation?

• those in the tidal pools

• those in the sunlight level of the ocean

• those in the twilight level of the ocean

• those in the deep level of the ocean

A population cycle is

• how many of a species are in the population

• a very rare event that is difficult to document

• the result of varying temperatures in the ocean

• a predictable increase and decrease in a population

A trophic cascade must

• be caused by an apex predator

• result in the extinction of a species

• require human intervention to resolve

• involve several levels of the food pyramid

The addition or removal of a species causes a trophic cascade.

• True

• False