Which part of the plant cell is primarily responsible for using energy from sunlight to synthesize sugar during photosynthesis?

• A. Mitochondrion
• B. Vacuole
• C. Nucleus
• D. Chloroplast

Answer: (D)

Verified step by step guidance

1. Understand the process of photosynthesis: Photosynthesis is the process by which plants convert light energy from the sun into chemical energy stored in sugars. This process requires specific organelles and molecules.
2. Identify the organelle responsible for photosynthesis: In plant cells, the chloroplast is the organelle that contains chlorophyll, a pigment that captures sunlight and initiates the photosynthesis process.
3. Review the role of chloroplasts: Chloroplasts have a double membrane and internal structures called thylakoids, where the light-dependent reactions of photosynthesis occur. These reactions produce energy carriers (ATP and NADPH) used in the next stage.
4. Understand the synthesis of sugar: In the stroma of the chloroplast, the light-independent reactions (Calvin cycle) use the energy carriers from the light-dependent reactions to convert carbon dioxide into glucose (a sugar).
5. Eliminate incorrect options: The mitochondrion is involved in cellular respiration, the vacuole stores substances, and the nucleus contains genetic material. None of these are directly involved in photosynthesis. Therefore, the correct answer is the chloroplast.