Read the pages in the text indicated by Z-15 and study Behavioral Objectives 21 and 22. Differences in climate over the globe for billions of years have resulted in the formation of many diverse terrestrial and aquatic biomes. These biomes have distinct characteristics as to assemblages of plants, animal, and microorganisms that separate them from one another. These differences are due to major circulation patterns of the atmosphere and the oceans, driven by unequal distribution of heat from the sun.

 Activity: What factors controlled by these differences do you think will determine the pattern of growth for living organisms within each biome? Four factors are listed below. Write a paragraph in you notes how plants and animals may develop adaptations to compensate for both extremes for each of these factors.

• Rainfall (water)
• Temperature
• Light (duration length of day)
• Light (strength)