Cells

Cells are the smallest parts of living things. You cannot see them without a microscope. Every part of your body is made of cells. Plants, animals, and even tiny germs are made of cells too.

Parts of a Cell

Cells are like tiny rooms with special parts inside. The nucleus is the brain of the cell and holds DNA. The outside is called the cell membrane and keeps the cell together. Inside are small parts that give the cell energy and make things it needs.

Types of Cells

Your body has many different kinds of cells. Skin cells protect you on the outside. Muscle cells help you move. Nerve cells send messages, and blood cells carry oxygen around your body.

Fun Facts

• Your body has about 37 trillion cells.
• The biggest cell you can see is a bird's egg yolk.
• Most of your cells are replaced every few years.

Did You Know?

Cells were first seen in 1665 by a scientist named Robert Hooke. He was looking at a piece of cork through a microscope.