Question

multiple choice 1 point
carbohydrate - synthesizing reactions of photosynthesis directly require
light
chlorophyll and co₂
o₂ and h₂o
darkness
products of the light reactions

Explanation:

Photosynthesis' light - dependent reactions need light. Chlorophyll absorbs light energy. \(CO_2\) is used in the Calvin cycle (dark reactions). \(O_2\) and \(H_2O\) are not direct requirements for the light - synthesizing reactions. Darkness is the opposite of what's needed. The products of the light reactions (like ATP and NADPH) are not the requirements asked here. The key requirement for the light - synthesizing (light - dependent) reactions of photosynthesis is light.

Answer:

light