All the living things actually do something in common. They are all made of tiny units called cells. The huge elephant is made of hundreds of billions of cells, and there are little animals whose whole body is formed of a single cell. The human body, too is made of cells-billions of them.
Cells look like.
most cells are so small that you need a powerful magnifying lens to see one. Some cells are so small that you could put 2,50,000 of them on the dot you put at the end of this sentence. There are also some which are large enough be seen with naked eyes. Among these large cells are root hairs of plants, certain seaweeds and the eggs of animals.
Cells are of many shapes. Some are round. Others look like bricks with rounded corners. Still others are long and hairlike. Some cells are shaped like plates, cylinders, ribbons or spiral rods.
Parts of cell
If you look at a single cell from a human body, through a microscope you can see that the cell surrounded by a membrane. This is the cell membrane. It surround the cell in the same way that a balloon surrounds the air within it.
Within the cell membrane is a material that has grainy appearance. This material is cytoplasm, which flows about within the cell membrane. Cytoplasm distributes nourishment within the cell and gets rid of the cell’s waste products.
Within the cytoplasm is a large dot. This dot is really a sphere and is the cell’s nucleus. This nucleus is the most important part of the cell. It directs the cell’s living activities. The way in which the cell uses nourishment and oxygen, the way the cytoplasm get rid of wastes, the way the cell reproduces all these functions are regulated by the nucleus. If the nucleus is removed the cell dies.
Materials used for making cell.
The cell membrane, the cytoplasm and the nucleus of the cell are made of a material called protoplasm. Protoplasm is a living material and makes a living cell “alive”. Scientists have found protoplasm to be made of water and many other chemical substances. Although scientists know what these substances are and how much of each there is in protoplasm, no scientist thus far has been able to put them together properly so as to make living protoplasm. This shows that protoplasm is a very complex material. Subscribe to Child Project Helper by Email
