General

As we all know, in order to build a large building, small components are put together to form a solid structure. Similarly, if I want to build a wall, I need small units called bricks.

In the same way, when the body of a living creature is formed, it is made up of small units that combine to create a single living being. These small units are called cells. Scientists define the cell as the structural and functional unit of living organisms.

If you carefully pay attention to the definition, it states that the cell is the structural unit of the body of every living organism. For this reason, when the body of a living organism is made, cells take on different shapes. For example, they can be cylindrical, polygonal, spherical, etc. Whenever the shape of a cell changes, its function also changes.
A cell has three basic components:

1. The cell membrane or cell wall (in some cases, both the cell membrane and the cell wall)
2. The cytoplasm
3. Nuclear materials

The cell membrane of animal cells is made of phosphate, glucose, and lipids. There are small holes in this membrane that help in the exchange of materials between the inside and outside of the cell. In plant cells, this membrane is called the cell wall, and it is made of a sugar called cellulose. The second part of the cell is the cytoplasm, which is usually gelatinous. It contains the essential components needed for the cell's important functions, such as cellular respiration and energy production.

The third component includes nuclear materials, such as RNA and DNA. In living organisms, there are two types of cells: eukaryotes and prokaryotes. In conclusion, all living things are made of small units called cells. These cells have three basic components, come in different shapes, and perform various functions.