Certified Crop Advisor Practice Exam

The process of photosynthesis primarily occurs in the __________ of plants.

1. roots

2. leaves

3. stems

4. flowers

The correct answer is: leaves

The process of photosynthesis primarily occurs in the leaves of plants. Leaves are equipped with chloroplasts, which contain chlorophyll, the green pigment responsible for capturing light energy from the sun. Through photosynthesis, plants convert light energy into chemical energy, producing glucose and oxygen as byproducts. The structure of leaves, with their broad surface area and thinness, maximizes light absorption and gas exchange, making them the most efficient organs for this critical process. In contrast, while roots are essential for nutrient and water uptake, they lack chlorophyll and are not involved in photosynthesis. Stems support the plant structure and can occasionally perform limited photosynthesis, especially in certain plants that have green stems, but they are not the primary site. Flowers primarily function in reproduction and, while they may contain some photosynthetic tissue, do not play a significant role in the overall process of photosynthesis compared to leaves.