Do flowers only exist to make plants look pretty?
Springtime is when nature appears to come back to life after winter. Trees grow leaves, grass gets green, and flowers sprout, displaying beautiful colors and sometimes spreading a delightful scent. But have you ever looked at a flower in more detail? What parts do flowers consist of? Are all flowers alike? In this activity you will find out by dissecting, or taking apart, a flower piece by piece. How many plant parts do you think you can identify?
Plants that make flowers are known as flowering plants. But do flowers only exist to make plants look pretty? Not quite! Although they can be beautiful to us, flowers are made to attract pollinators for reproduction. This means the flowers are a crucial part of the process in growing seeds to make more plants. If you look closely at a flower, you might see that it is made of many different parts, each of which has a specific purpose.
Some flowering plants have a stem, which is a long stalk that carries water and nutrients and supports the flower. Leaves produce the food for the plant by photosynthesis, a process that helps makes plant food from light, carbon dioxide and water.
When you look at the flower of a flowering plant, the most obvious parts are probably the petals. They can vary in size and shape but are usually brightly colored. Their purpose is to attract the bees and other insects that help to pollinate the plants. You might be surprised to learn that some flowers—in the botanical world they are called "perfect flowers"—have male parts and female parts, and each plays an important role during pollination.
The male parts, called stamens, look like long stalks (known as filaments) with a little round shape at their end (called the anther), which contains the plant pollen. This bright yellow or orange dust is what insects carry from one plant to another. Pollination occurs if the pollen gets carried to the female parts of a new flower, called the pistil. The pistil is usually a long stalk located in the center of the flower and is also made up of several parts. Most importantly it contains the ovary at its bottom, which houses the female plant eggs called ovules. When pollen is dropped into the pistil of a flower, the eggs, or ovules, inside the plant ovaries are fertilized. The fertilized ovules then grow into plant seeds, and the ovary becomes the fruit.
As you can see, a flower is much more than just beautiful to look at: it is essential for a plant to create more plants. Take a closer look at the many different plant parts in this activity, and see how they differ from one flower to another!
Just from looking at your flowering plants you might have noticed that each plant looks quite different. Obvious differences, for example, are the size or color of a flower. When you dissected the plants, however, you should have been able to identify the same plant parts for each of your plants. Each of them should have had a stem, which might have had some green leaves on it; colorful flower petals; the female flower part (pistil) at the center of the flower; and the male plant parts (stamen) that produce the pollen. When you compare each plant part you might have noticed that they each look very different. A petal, for example, probably looked very different from the stem. This is because each plant part has a specific function, and its appearance is optimized to fulfill that function.
If you compare the same plant parts between different flowers, you might have observed that they looked somewhat similar. They might not have looked exactly the same, but you should have seen that they have the same functional features. Although flower petals can differ in size and color, they are usually brightly colored or shaped in a way to attract pollinators, such as bees. The differences between different flowering plants allow us to identify different plant species.
This experiment was selected for Science at Home because it teaches NGSS Disciplinary Core Ideas, which have broad importance within or across multiple science or engineering disciplines.
Learn more about how this experiment is based in NGSS Disciplinary Core Ideas.