Question

which of the following statements about c4 carbon fixation is not true?
a. c4 carbon fixation is an adaptation for plants exposed to high light intensity.
b. c4 carbon fixation occurs in more plants than c3 carbon fixation.
c. c4 carbon fixation is more common in areas of high temperatures than c3 carbon fixation.
d. c4 carbon fixation occurs in the inner cells of a leaf rather than the entire leaf.

Explanation:

• Option a: C4 plants are adapted to high light intensity as they can efficiently use light energy.
• Option b: C3 carbon fixation occurs in more plants than C4. C3 is the most common pathway.
• Option c: C4 is more common in high - temperature areas as it reduces photorespiration which is more of a problem in high temperatures.
• Option d: In C4 plants, carbon fixation occurs in mesophyll cells (outer - like cells in a sense) for the initial fixation and then in bundle sheath cells (inner cells) for the Calvin cycle.

Answer:

B. C4 carbon fixation occurs in more plants than C3 carbon fixation.