Complete the following essays on your own paper.   Just saying pollution or air pollution for any answer is not acceptable.

1.   Some problems in the biosphere are listed below.  (Total 81 pts.)

Ecological Problems

Global warming
Destruction of the ozone shield
Acid Precipitation

Discuss these ecological problems.  For each of the ecological problems above be sure to state:

• the problem you selected, the gas released causing the problem and one human action that may have caused the problem   
• one way in which the problem may negatively affect humans
• one positive action that could be taken to reduce the problem

Hint:   This question could easily be done using a chart such as the following one.   Your chart will need
to be expanded on your own paper and occupy more area than mine.  J

Use the reading passage below and your knowledge of biology to answer questions 2 and 3 which follow.

Plastics Produced by Plants

Plastics are generally thought of as materials made exclusively by human technology.
However, some plants and bacteria naturally make small amounts of plastics. Furthermore,
unlike synthetic plastics, plastics produced by plants and bacteria break down easily in the
environment. Synthetic plastics, which are produced from petroleum, are the fastest growing
type of waste in the United States . Researchers are learning how to greatly increase the
amount of plastic made by plants. One day farmers may grow crops of plastic-producing
plants in addition to wheat and corn crops.

A researcher at the Carnegie Institution of Washington was one of the first to attempt to
use plants to make plastics. He knew that a common bacterium, known as Alcaligenes
eutrophus, naturally produced a plastic called polyhydroxybutyrate (PHB), which resembles
the type of plastic used to make garbage bags.

However, growing bacteria to produce plastic can be expensive. In order to determine if
genetically engineered plants could make plastic, genes were isolated from A. eutrophus
and inserted into plants. After a few tries, the researchers were able to produce healthy
plastic-producing plants.

2.  By what process were the plastic-producing plants developed?   (9 pts.)

3.   Explain why the use of the plastic produced by these plants is better for the environment
than plastic produced by human technology, and explain why this plastic would
be a benefit to future generations.   (9 pts.)