Hormone or growth regulators, also known as systematic herbicides, are typically absorbed through which part of the plant?

The correct answer is the leaves. Systemic herbicides, or growth regulators, are designed to be absorbed by the plant and translocated throughout its tissues. Leaves are the primary site of absorption because they are equipped with stomata and a waxy cuticle, which facilitate the uptake of chemicals. Once absorbed, the herbicide moves through the vascular system of the plant, affecting various physiological processes.

While roots can absorb certain nutrients and water, they are not the main point of entry for systemic herbicides. The stem also has some capacity to absorb but is not as effective as the leaves. Flowers, while vital for reproduction, do not absorb herbicides significantly since their primary function is not interception of nutrients or chemicals. Thus, the leaves are the most effective and common entry point for these herbicides, making this choice accurate in the context of how plants uptake systemic herbicides.