Question

how is photosynthesis similar in c4 plants and cam plants?
in both cases, electron transport is not used.
both types of plants make sugar without the calvin cycle.
in both cases, rubisco is not used to fix carbon initially.
both types of plants make most of their sugar in the dark.

Explanation:

• In C4 plants, PEP carboxylase initially fixes carbon (not rubisco). In CAM plants, PEP carboxylase also initially fixes carbon (not rubisco).
• Electron transport is used in both (so the first option is wrong).
• Both use the Calvin cycle (so the second option is wrong).
• CAM plants open stomata at night for carbon fixation but still need light for the light - dependent reactions related to sugar production (so the fourth option is wrong).

Answer:

In both cases, rubisco is not used to fix carbon initially.