Where do producers, such as plants, primarily obtain the energy required for photosynthesis?

• A. Oxygen in the atmosphere
• B. Heat from the Earth's core
• C. Organic molecules from other organisms
• D. Sunlight

Answer: (D)

Verified step by step guidance

1. Understand the process of photosynthesis: Photosynthesis is the process by which producers, such as plants, convert light energy into chemical energy stored in glucose. This process primarily occurs in the chloroplasts of plant cells.
2. Identify the energy source for photosynthesis: The energy required for photosynthesis comes from sunlight, which is absorbed by pigments like chlorophyll in the chloroplasts.
3. Eliminate incorrect options: Oxygen in the atmosphere is a byproduct of photosynthesis, not an energy source. Heat from the Earth's core is not accessible to plants for energy. Organic molecules from other organisms are consumed by heterotrophs, not autotrophs like plants.
4. Recognize the role of sunlight: Sunlight provides the photons necessary to drive the light-dependent reactions of photosynthesis, where water is split and energy carriers like ATP and NADPH are produced.
5. Conclude that sunlight is the primary energy source for photosynthesis, as it initiates the entire process by providing the energy needed to convert carbon dioxide and water into glucose and oxygen.