Final answer:
A healthy stoma is a small pore surrounded by guard cells that regulate gas exchange in plants. The guard cells may resemble lips when magnified. A healthy stoma should have open and functioning guard cells.
Step-by-step explanation:
A healthy stoma refers to the opening found on the surface of plant leaves that allows for gas exchange. When inspecting a healthy stoma, it should appear as a small pore surrounded by specialized cells called guard cells. These guard cells regulate the opening and closing of the stoma to control the exchange of gases like carbon dioxide and oxygen.
On the surface of a leaf, stomata are visible under a microscope. They can be observed as small pores or openings that are scattered across the leaf's surface. When magnified, the guard cells that surround the stoma may resemble lips that enclose the opening, giving it a distinct appearance.
Overall, a healthy stoma should have open and properly functioning guard cells, allowing for efficient gas exchange between the plant and its environment.