The most important role of pigments in photosynthesis is to _____.

• A. produce ATP directly from carbon dioxide
• B. absorb light energy for use in the light-dependent reactions
• C. break down glucose into usable energy
• D. transport water from roots to leaves

Answer: (B)

Verified step by step guidance

1. Understand the process of photosynthesis: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. It consists of two main stages: light-dependent reactions and the Calvin cycle (light-independent reactions).
2. Recognize the role of pigments: Pigments, such as chlorophyll, are molecules that absorb specific wavelengths of light. They are crucial for capturing light energy during the light-dependent reactions of photosynthesis.
3. Clarify the light-dependent reactions: In these reactions, pigments absorb light energy, which excites electrons. These high-energy electrons are then used to produce ATP and NADPH, which are essential for the Calvin cycle.
4. Eliminate incorrect options: The statement 'produce ATP directly from carbon dioxide' is incorrect because ATP is produced from the energy captured by pigments, not directly from carbon dioxide. Similarly, 'break down glucose into usable energy' refers to cellular respiration, not photosynthesis. 'Transport water from roots to leaves' is a function of the plant's vascular system, not pigments.
5. Conclude the correct role: The most important role of pigments in photosynthesis is to absorb light energy for use in the light-dependent reactions, enabling the plant to convert light energy into chemical energy.