1 - In the past, it is possible that early humans found caves and began living in them. Due to this human activity, they forced bears out of their homes and caused their survival rate to decrease. Explain how this situation is a form of pollution and why the bear had difficulties surviving.

2 - Using the activities described below (1-5), describe the relationship that exists in each; mutualism, predation, parasitism, competition, and commensalisms and provide an explanation for

each situation.

1. Pollination of flowers

2. Praying Mantis Eating a Bee

3. Flees Living and feeding on a human

4. Trees attempting to grow higher than one another to obtain sunlight

5. Birds feeding on insects that are stirred up by grazing animals

3 - After analyzing the nitrogen cycle, explain why the nitrogen cycle is a crucial piece to the

survival of all ecosystems and why nitrogen is important to all organisms.

4 - Explain how plants play a crucial role in the carbon cycle. Be sure to describe how the following items affect the carbon cycle:

How the location of the plant in its ecosystem effect

Photosynthesis

Cellular respiration