A cell in the leaf of a green plant performs both photosynthesis and cellular respiration, often at the same time. Which statement best describes how these processes are related to each other?

Question

a
Both processes require energy directly from the Sun.
b
Thermal energy from one process is used as the primary energy source for the other process.
c
Products of one process are used as some of the reactants for the other process.
d
Both processes produce carbon dioxide.

Answer 1

The statement that best describes how photosynthesis and cellular respiration are related to each other is:

c. Products of one process are used as some of the reactants for the other process.

In photosynthesis, plants convert carbon dioxide and water into glucose and oxygen using solar energy. In cellular respiration, plants (and other organisms) use glucose and oxygen to produce energy (ATP), releasing carbon dioxide and water as byproducts. Thus, the products of photosynthesis (glucose and oxygen) serve as reactants in cellular respiration, and vice versa for the processes.