Hint: The cell was discovered by Robert Hooke in the thin slices of cork under a self-made microscope. He observed cells as small compartments when he viewed through the microscope.
As we know that all living organisms are made up of cells and all the cells are made up of molecules. The different types of elements such as carbon, nitrogen, oxygen, and phosphorus help in forming the different components of the cells and represent it as a living unit. The cells provide structure and processes nutrients and convert them into usable energy in both unicellular organisms and multicellular organisms.
The cells are also called the functional unit of life because they are independent and a single cell can perform the activity of nutrition, excretion, and they detect and respond to their environment, they move, breathe, grow, and reproduce also. The multicellular organisms are having specialized cells for performing specific functions. For example, the blood contains RBC which is responsible for the transport of Oxygen and Carbon dioxide. Photoreceptor cells found in our eyes are responsible for converting light into signals and the signals are carried by the specialized nerve cells to the brain.
Living organisms represent a high degree of organization that has a natural tendency to get disorganized due to external environmental factors so our body tries to continuously conduct maintenance and repairing activities for which molecular moment is necessary. In multicellular organisms, simple diffusion is not effective like a unicellular organism, as all the cells are not in direct contact with the environment so in the multicellular organisms to conduct these activities a system is developed and we know that the cell is the basic unit of this system also.
- The cells are very much useful for performing various life processes that are required for the stability of life.
- The multicellular organisms are having specialized cells for performing specific functions.
- In unicellular organisms, the entire surface of the body is in direct contact with the environment so simple diffusion is effective enough to help in the exchange of gases and removing toxic wastes.
- In multicellular organisms, different systems have been developed to conduct the various functions of the organism.