How do systemic herbicides function within plants?

Systemic herbicides function by being absorbed into the plant's tissues and then translocating throughout the plant. This means that once the herbicide enters the plant, it can move through the vascular system to reach various parts, including leaves, stems, and roots. This allows for effective control of the plant because the herbicide can affect not just the area where it was applied, but the entire organism.

Choices that suggest the herbicide stays on the surface or only affects the roots misunderstand how systemic action works. Systemic herbicides are designed to penetrate through the plant tissues, rather than just remaining on the surface or targeting isolated parts. Additionally, the idea that they kill solely through contact does not accurately describe systemic herbicides, as contact herbicides work differently by causing damage at the point of contact without moving through the plant.