Do you ever spit watermelon seeds at your brother or sister? Have you ever planted a tomato or bean seed in a plastic cup and watched it grow? If so, you are familiar with seeds and how they develop.

SEEDS AND FRUIT

Seeds are made up of several parts -  the cotyledon, protective sheaths, and the seed coat are only a few. A typical corn kernel would look like this if you were studying it through a microscope.

The growing shoot and root of the embryo is contained within the protective sheaths. The area of the seed that is stained blue is called endosperm, and it nourishes the embryo as it develops.  The seed coat protects everything inside the seed.  The cotyledon nourishes the seed after it germinates and as the young plant begins to grow.

In some plants, many ova may be fertilized in the same ovary. In others, there is only one egg per ovary. The seeds and the ovary develop at the same time, and the number and size of the eggs fertilized determines how large the fruit will grow. If there are many seeds, the ovary will swell up to a very large size, like in watermelons or pumpkins. If the seeds are small and few in number, the fruit won't be very large, like in apples and cherries. But it will definitely be big enough and nutritious enough to support all the seeds inside as they develop.

Here are some seeds that have already developed inside the fruit. Can you see them all? If you planted a seed like this and took good care of it, chances are a wonderful little plant would grow and produce seeds and fruit just like you see here. By the way, can you name the "fruit" you're looking at? Of course you can, but you may be thinking that two of them are vegetables! Well, tomatoes and peppers are actually fruit because they produce the fleshy, protective ovaries that your mom may think are good for you to eat (you may disagree!), but since they are not sweet like kiwis and strawberries, or tangy like lemons, we call them vegetables! Do you know of any seeds that are good to eat?

Plants, however, don't produce fruit and seeds simply for our health and enjoyment. Fruit serves to disperse the seeds the plant produces, which is very important. Animals can carry the fruit to new places, eat it, and leave the seeds there. This gives the seeds a good chance to grow in an area where conditions may be more favorable. The wind is also helpful to seed dispersal, just like it can be helpful to pollen dispersal. Here are some seeds that can be carried by the wind. Do they look familiar to you?

Now you know all about how and why a flower develops fruit!
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FRUIT DEVELOPMENT or
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