Introduction to Cell BiologyIntroduction to Cell Biology illustrate about the evolution of the cell that involves two processes:1) Occurrence of genetic variations which are passed on from one generation to another; and2) Selection of those genetic changes which are useful for the survival and propagation of the organism.Discovery of the cell as a structural unit of life was possible with the development of the microscope. It is interesting to learn as to how the present day cell evolved from smaller components and then became a building block for larger structures. You will study that molecules which were capable of self-replication and carrying genetic information were evolved first. These molecules then got enclosed in a membrane, to give rise to the first ancestral cell which could propagate its own self. The development of mechanisms for photosynthesis and respiration in the early cells led to the evolution of procaryotes (e.g. bacteria) first and then to eucaryotes (higher animals and plants). Although the basic structure of plant and animals cells is similar, they differ in certain aspects such as the absence of large vacuoles and cell wall in animal cell. You will study about the differences between plant and animal cells.