Robert Hooke "saw" cells for the first time with the help of a microscope. Now, scientists have found that the vast majority of cells are between 10 and 100 microns in diameter, and the true colors of these cells cannot be seen with the naked eye alone. But human nerve cells are more than 1 meter long. Can we see these nerve cells? The answer is no. Although the nerve cell is 1 meter long, it is a very thin fiber. No matter how long the thin filament is, it is impossible to see. Moreover, it is colorless and transparent. When it is not stained, people cannot distinguish them at all. Even using a microscope to observe nerve cells, they need to dye the nerve cells with dye!
The world of cells can be said to be dazzling and dazzling. Although most cells are so small, there are still some "giants" like Shrek. A human egg cell is as big as a needle tip, but it is not so easy for the best eyes to see clearly an egg cell as big as a needle tip. So is the egg that we can see clearly a cell? In fact, an unhatched egg does contain an egg cell or a fertilized egg cell, but the egg shell and egg white are not components of the egg cell. When we crack open the egg shell and pour the yolk and egg white into a bowl, we will see a small white spot. The scientific name of this spot is blastoderm, which contains the nucleus of the cell. In addition, chicken egg cells also contain structures such as cytoplasm, cell membrane and nuclear membrane. It is not easy to distinguish these parts of chicken egg cells with the naked eye.