Exam 37: Communities and Ecosystems

Biological control is defined as

Denitrifying bacteria convert to .

Which arrow shows nitrogen fixation?

Organisms that digest molecules in organic material and convert them into inorganic forms are

In a food chain consisting of phytoplankton -zooplankton -fish -fishermen,the fishermen are

Which trophic level in this food chain represents the secondary consumer?

You want to do all that you can to safeguard the environment by preserving energy.One simple thing that you can do is to eat a diet consisting only of organisms that are

Within an ecosystem,a tree is a

During ecological succession,the species composition of a plant community generally

Which of the following substances is cycled between organic matter and abiotic reservoirs?

If an overlap develops between the ranges of two closely related species,and if the species occupy the same niche in the zone of overlap,what will probably happen in the zone of overlap?

One mechanism that prey populations evolve to avoid predation is

Which of the following statements about the nitrogen cycle is true?

Carbon mainly cycles between the biotic and abiotic worlds through the processes of

On Earth,most organic molecules are produced by

The flow of into ecosystems occurs in one direction only,while are recycled within the ecosystem itself.

Which of the following ecological problems might result from fertilizing a golf course with phosphorus- rich fertilizer?

An owl and a hawk both eat mice.Which of these describes the relationship between a hawk and an owl?

For a given area and time period,the amount of solar energy converted to chemical energy in organic compounds is called

We expect that a keystone species that is a predator will