Exam 20: Ecosystems

Phosphorus is an essential element in all living things and is a component of

The loss of _____ that occurs at each trophic level places a limit on how many top-level carnivores a community can support.

Highly productive lakes with an abundance of organic material are called

When the energy flow through an ecosystem is measured at each trophic level,__________ of the available energy passes from one level to the next.

_______________ are found halfway between the equator and poles,cover the interiors of major continents,and have been largely converted to agricultural use.

Several food chains woven together comprise a ______________.

The ___________________ region is the part of an ocean's shallow water zone that is exposed to air whenever the tide recedes.

Which part of the lake contains numerous bacteria and wormlike organisms that consume dead debris?

Which is incorrect about deep-sea organisms?

Life exists on Earth because of the constant flow of light energy from the sun that is transformed into chemical energy.

Devise an example of a food chain with four links.

Certain bacteria are capable of transforming atmospheric nitrogen into a form other organisms can use through a process known as

The moisture that travels up from the plants and into the atmosphere falls back to the earth as rain.

All of the following are examples of detritivores except

In the annual cycle of a temperate lake,thermal stratification occurs when?

Uncontrolled growth of algae in an aquatic ecosystem is due to a process known as ________________ caused by excessive inputs of nutrients.

Herbivores are at what trophic level within an ecosystem?

____________ is characterized by unusually warm ocean temperatures in the eastern Pacific.

Why would few reptiles be found in the tundra?

A ___________ is a type of major land ecosystem determined mostly by the features of the climate in the area.Many are actually named for the dominant plants or lack of.