How Shape Helps Things Work

By the end of this lesson, you will be able to explain how the shape of something helps it do its job.

Everything around you has a structure, which means the parts it is made of and the way those parts are put together. Everything also has a function, which is the job it does. When you look closely, you will see that the structure almost always matches the function. The shape is not an accident. It helps the job get done.

Think about a school bus in Texas. A bus has big wheels, a strong frame, and rows of seats inside. Those parts are its structure. Its function is to carry many students safely to school. Now imagine a bus with only one seat, or with tiny wheels the size of quarters. It could not do its job. The structure has to fit the function.

Living things work the same way. A mesquite tree has long roots that reach deep into dry ground. That structure helps the tree do the job of soaking up water. A mockingbird has light, hollow bones and wide wings, so it can fly. A cactus has thick stems that store water and sharp spines that keep animals away. Each part has a shape that helps the plant or animal survive.

Bigger groups of parts form a system, which is a set of parts that work together to do something. Your body has a skeletal system. Your leg bones are long and strong so you can stand, walk, and run. Your skull is round and hard so it can protect your brain. Same body, different shapes, different jobs.

So when you see something new, ask yourself two questions. What is this part shaped like? What job might that shape help it do?

Try it: A duck has webbed feet that are flat and wide, so what job do you think those feet help the duck do?