What is the primary function of leaves in plants?

Leaves are primarily responsible for photosynthesis, a process that enables plants to convert sunlight into chemical energy. This involves harvesting sunlight through chlorophyll, the green pigment found in leaves, which captures light energy. During photosynthesis, carbon dioxide from the atmosphere and water absorbed by the roots are combined to produce glucose, a type of sugar that serves as food for the plant, and oxygen is released as a byproduct. This process is vital not only for the plant's survival but also plays a crucial role in the ecosystem as it contributes to the oxygen supply and serves as a foundational element in the food chain.

The other options describe functions that do not align with the primary role of leaves. Nutrient absorption occurs mainly through the roots, structural support is provided by the stem and other parts of the plant, and the transport of water takes place through specialized tissues such as xylem, rather than the leaves themselves. Understanding these distinct functions highlights the unique and essential role leaves play in a plant's life cycle and overall health.