Final answer:
Broccoli is eaten for its immature flower buds, which are attached to a portion of the plant's stem.
Step-by-step explanation:
When we eat broccoli, we are primarily eating its flower buds. These are the parts of the plant that are clustered together in a tree-like formation on top of the stem. Broccoli is an example of a plant where we consume the flowers before they fully bloom. The entire structure we eat includes both immature flower buds and a portion of the stem. The stem is characterized by nodes (points of attachment for leaves or branches) and internodes (regions between nodes), and it connects the roots to the leaves, helping with water transport and carrying the products of photosynthesis throughout the plant.