Some bacteria reduce metal ions or other inorganic substances. Is this behavior a clue that these organisms are chemoautotrophs? Explain.

Describe how the structure of the chloroplast relates to its function in photosynthesis.

Could a seed produce a plant if its endosperm were removed before it germinated? Why or why not?

Some deep-earth bacteria consume petroleum or natural gas. Are these organisms chemoautotrophs?

Are the light reactions necessary in the mesophyll cells of $C_4$ plants? Explain the reasons for your answer.

What are the products of the light reactions, and how are they used?

What is the relationship between the light reactions and the carbon dioxide–fixing reactions of photosynthesis?

Describe the location and function of the two systems of carbon dioxide fixation in $C_4$ plants.

How do chemoautotrophs obtain organic nutrients?

The curve in Figure $4.16$ shows the effect of temperature increase on the rate of photosynthesis in a typical $C_3$ plant. Construct and explain a curve showing the response of a $C_4$ plant to the same increase in temperature.

In what ways is photosynthesis important to humans?

How is light used in photosynthesis?

Describe the process of photorespiration. What is its effect on the rate of photosynthesis?

Why are chemoautotrophs rare among familiar organisms?