Texas Science Teacher Resource Hub

Plants have different structures depending on where they live. A cactus has thick stems and spines instead of wide leaves because it lives in the desert. A pond plant has light, hollow stems so it can float. A pine tree has skinny needle-shaped leaves because it lives where snow could break wide leaves. Same general idea (a plant), but the structures are tuned to the environment.

Roots have two main jobs. They anchor the plant in place AND they pull water and nutrients up from the soil into the plant. Deep roots reach down to find water in dry environments. Shallow, spread-out roots collect water from light rain. Both designs work, depending on where the plant lives. The structure of the roots fits the environment.

The waxy coating on a leaf does an important job. It keeps water from evaporating out of the leaf, which is critical in dry, sunny places. The wax is like a built-in raincoat. The shine is just a side effect. Plants like holly, magnolias, and many desert plants all have waxy leaves because their environments dry out fast and the wax holds water in.

Plants are constantly fighting to survive: hot weather, cold weather, dry soil, hungry animals, blocked sunlight, lack of water. Their structures are what let them deal with each of those problems. Without the right roots, leaves, and stems for their environment, the plant would die. The whole reason plants have so many different shapes is because each kind has solved a different survival problem.