Plant Biology Practice Test

Nodes are the spots on a stem where leaves attach and where buds may form. This is the specific point that marks the connection between leaf, stem, and the plant’s vascular system, with the leaf typically connected by a petiole at that site. The segment between two nodes is called the internode, which explains how the stem lengthens over time. Petiole refers to the leaf stalk that attaches the leaf blade to the node, not the attachment point itself. Pith is the central tissue inside the stem, not an attachment site. Organ is a general term for a major plant part, like a leaf or stem, rather than the exact attachment point.