Consider the chemical process of photosynthesis. In this process, ...

[B]

Consider the chemical process of photosynthesis. In this process,
 
  a. energy is absorbed by the chlorophyll in plants.
  b. water and carbon dioxide are turned into sugar.
  c. oxygen is given off.
  d. all of the above phenomena occur.
  e. only (a) and (c) may occur.

Question 2

Why is the food-for-oil tradeoff possible? Explain how availability or lack of availability of energy influences the agricultural system.
 
  What will be an ideal response?

[ndhahbi]

Answer to Question 1

D

Answer to Question 2

When external energy is not available, as in traditional agriculture human labor is
necessary. Farm animals can reduce human labor, but it does not eliminate it. Working
behind a plow is hard work (though not as hard as doing it without the animal).
Machines can do many of these things faster and with less effort required of the farmer. It
becomes very attractive to reduce the hard work that wore out so many of our ancestors and
replace that by machines that are fueled by petroleum-based products. Thus, we plow oil
and raise crops.

[B]

Thanks for the timely response, appreciate it

[xiazhe]

Gracias!