Exercises

Question 11.1

Can the biosphere be considered an Earth system? How would that system be described?

Question 11.2

How do autotrophs differ from heterotrophs?

Question 11.3

What is metabolism?

Question 11.4

In what environments might you find extremophiles? Can humans live under extreme conditions?

Question 11.5

What is the difference between photosynthesis and respiration?

Question 11.6

Explain how life is related to water. What would happen if all the water on Earth turned to ice?

Question 11.7

Draw a diagram of a biogeochemical cycle. What are the inputs and outputs? What are the processes that power the cycle?

Question 11.8

Carbon is regarded as the starting point for all of life. What else is important?

Question 11.9

In the diagram shown in Figure 11.12, how many period boundaries of the geologic time scale are marked by mass extinctions? How many era boundaries are marked by mass extinctions?

Question 11.10

What controls the habitable zone around stars? Is Neptune in the habitable zone of our solar system?