How small is a human cell


This living being consists only of its single cell. It is a single cell, namely a paramecium. The place where it digests food is colored red.

A cell is a small place. We know the prison cell or the cell in a monastery where a monk or a nun lives. Often one thinks of a cell from biology, it is about living beings.

Cells are the smallest building blocks, like the bricks in a wall. But cells are so small that you need a powerful microscope to see them individually. It takes about 100 trillion cells for a whole person, that's a one with 14 zeros.

Almost all living things are made up of cells. Viruses that can make us sick are an exception. Simple living beings only consist of a single cell, which is why they are called “unicellular cells”. These are bacteria, for example. The majority of living beings, however, are multicellular, including us humans.

You can imagine a cell like a peach: The skin lies around the outside, which is the cell wall or the cell membrane. The peach stone corresponds to the cell nucleus. All the plans for the construction and work of the cell are in there. These plans are called genes.

The pulp of the peaches corresponds to the cell plasma. It is sometimes a little more fluid, sometimes a little more solid. However, the scientists have discovered many more parts in the cells. The mitochondria gain energy. Other components do other things as well.

How do cells multiply and develop?

A doubly divided cell became four cells.

Take a bird or a mammal like humans as an example. An egg cell develops in the mother. During fertilization, a man's sperm hatches into the egg cell. This creates something like the “primordial cell” of a new living being.

This cell doubles everything it contains. Then it divides into two cells. This is called "cell division" or, more technically, "mitosis". The two cells become four, then eight, and so on. At first these are stem cells because it has not yet been determined what will become of them.

The further the cells divide, the more differently they develop. This is how hair cells, kidney cells, muscle cells, skin cells and many others are created. A hair cell can then no longer become a kidney cell.

However, a cell doesn't last that long. Again and again new cells are created and the old ones die. This is normal for the body. He transports the dead cells away. It just doesn't always work that way. Every living being gets older and then dies once.

Cells can also develop in the wrong direction. This is how tumors and cancer develop. The body can fight some types of cancer, but sometimes it cannot. In many cases, modern medicine can still help.

  • Cancer cells under a microscope. The nucleus has been stained blue so that it can be seen better.