Read the following selections, and answer the questions 6 - 11.
Life Cycle
1 Life cycle is the term used to tell how a living thing is born, lives, and dies. Humans have two main stages of life. After growing in the mother for nine months, they are born as babies. Then, they slowly grow into adults.
2 Some mammals have life cycles like humans. They have babies, and those babies grow up into adults. One example is a blue whale. A blue whale has a baby whale (called a calf). Then, the calf grows up to be an adult blue whale.
3 Some animals are born as eggs, and then they hatch. For example, birds lay eggs. The eggs hatch, and the baby birds grow up into adult birds. Many reptiles, like snakes, begin as eggs too. Fish start out as eggs as well.
4 Insects are different. Their life cycle has more stages. They go through a process called metamorphosis (met-uh-mawr-fuh-sis). This means they change from one form into another. A moth is a good example. It begins as an egg. Then, it hatches into a larva. The larva grows into a caterpillar. The caterpillar makes a cocoon. When it comes out, it is a moth.
Seeing Metamorphosis in Action
5 Did you know that you can watch this process? Are there insects near your house or school? If so, that should make it easy. Over 80 percent of insects go through complete metamorphosis. But many insects can be small. Some are hard to see in all the stages.
6 Another idea is to watch an amphibian. These are animals such as frogs. They live in water when they are small. Then, they move to land. They lay eggs. They are bigger, so it is easier to see them change.
7 If you have a pond near you, you might be able to find frog eggs. Or, you may see tadpoles. If your parents let you, you can put a tadpole in a fishbowl. Be sure to read about how to care for it first. It eats algae and plants. You can feed it boiled lettuce. The tadpole will grow into a frog. You may need to wait a long time for it to become a frog, but soon, the tadpole will sprout legs. Then, it will lose its tail. Finally, it will be a frog. Here is how it works.
