What are the main structural parts of a leaf?

The main structural parts of a leaf are the petiole and the blade. The petiole is the stalk that attaches the leaf to the stem, allowing for support and transport of nutrients and water. The blade is the broad, flat part of the leaf, which is crucial for photosynthesis, as it contains the majority of the chloroplasts that capture sunlight.

In contrast to the other options, stipules are small structures that can be found at the base of the petiole in some plant species, but they are not considered a primary part of the leaf structure itself. The leaf margin refers to the edge of the leaf, while the leaf apex is the tip of the leaf. While these features play roles in the overall morphology of the leaf, they do not encompass the main structural components necessary for the leaf's function. Therefore, petiole and blade are indeed the primary parts that define the structure and functionality of a leaf in most plants.