Exam 23: Ecology, the Environment, and Us

The element molybdenum is vital in the process of nitrogen fixation.For which crop would molybdenum be most critical to ensure success?

PCBs were frequently used in electrical transformers.A young man digs in an abandoned industrial site,finding old transformers,and sells the copper wire from them to a scrap yard.What health problems might the young man have in the future?

A(n)________ is a diagram in which blocks represent each trophic level.

What are the differences between primary and secondary succession?

American Bison consume only plants,so we would say they are ________.

Park officials needed to repair the old mill dam in a state park and so had to drain the pond behind,killing all the animals and many of the plants in the water.After the pond reformed and many years passed,a certain species of fish established itself in the pond and remained there for more than 400 years.Which most directly describes the role of that type of fish?

The sequence of changes in the species that make up a community is called ________.

Match each definition in the first column to the correct term in the second column. -These are organisms that consume both live plants and animals to fulfill their metabolic requirements in an ecosystem.

Alfalfa plants occur symbiotically with bacteria that can convert nitrogen gas to ammonium in a process called ________.

The total physical,chemical,and biological requirements of a species are said to be its ________.

Match each definition in the first column to the correct term in the second column. -Water evaporation from leaves is called this.

Two human activities,burning fossil fuels and ________,are important causes of the increase in atmospheric carbon dioxide.

An area had no previous community and had no existing soil at first,but then living things started occupying the area.This situation would be called ________.

Match each definition in the first column to the correct term in the second column. -The animals that consume plants,algae,or cyanobacteria for their metabolic requirements.

The process by which light energy is used by plants,algae,and cyanobacteria to form sugar is called ________.

Dieldrin was a chlorinated hydrocarbon insecticide that was remarkably useful against termites because it did not seem to degrade when applied to wood.What issue would you expect with its use?

The interactions and exchange of energy between all feeding levels is known as a ________.

It is important for cattle to add proteins to their body,so which plant would be best for them to eat?

Match each definition in the first column to the correct term in the second column. -The animals that eat plants exclusively as their main energy source.

On average,about ________% of the energy in one trophic level is transferred to the next.