Human Life Cycle Lesson for Kids

Instructor: Tamira Butler-Likely

Tamira has taught college Science and has a PhD in Biochemistry.

The steps of growth that all humans go through are called the human life cycle. In this lesson, we will learn more about the six different stages of the human life cycle: prenatal, baby, childhood, teenage, adulthood, and elderly.

The Human Life Cycle

Today, the average American lives to be 79 years old, though human life expectancy is different depending on where you live and other factors. During these years, most people go through the six stages of the human life cycle, which starts at the prenatal stage when fertilization takes place and ends with death. Let's learn more about the six main stages of life.

Prenatal Stage

Just like flowers grow from seeds that have been fertilized, so do humans! In humans, the seed is called an egg, and the fertilizer is called a sperm. When the egg and sperm combine, they form a zygote, which is smaller than the period at the end of this sentence. Over 40 weeks, the zygote grows into a fetus the size of a small watermelon. All this time, the fetus has been in its mother's womb. Now, it's time for the fetus to enter the world and begin the baby stage.

A fetus in the womb
Human fetus

Baby Stage

The baby stage lasts from birth to age one. Babies can't walk or talk yet, so they cry to communicate when they need something. As they baby's body and brain grow, the baby will start to move around on their own. At 6-8 months old, most babies can sit up and crawl. By one year old, babies usually have several teeth and are trying to talk.

Childhood Stage

If you're 12 or younger, you're in the childhood stage right now! Ages 1-12 make up the childhood stage, and this is when a lot of changes happen with our brains. We learn how to talk in complete sentences, how to feed ourselves, and how to read and write. Childhood is probably the most important stage in the human life cycle. Everything you learn and the habits you pick up will usually stay with you for the rest of your life.

Teenage Stage

The teenage stage, ages 13-18, is when a lot of changes happen with our bodies. The time when these changes happen are called puberty. Hair starts to grow in places that never had it before, our voices change, and the shape of our bodies change. Being a teenager can be a little rough as you get used to your new self--but remember, it won't last forever!

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