Cells, Human

THE CELL IS the structural and functional unit of all living organisms. In the study of cells, its classification is of prime importance. Cells can be broadly classified into two types: prokaryotic (Greek: before the nucleus) cells and eukaryotic cells (Greek: new nucleus). The prokaryotic cell differs from the eukaryotic cell by the absence of a true nucleus (double membrane bound structure containing genetic information), membraned organelles (subcellular structures having a distinct function), and has a 70 S ribosome.

The eukaryotic cells again can be further classified into plant and animal cells. Both the plant and the animal cell has a true nucleus, membrane bound organelles and an 80 S ribosome. In contrast to the plant cell, the animal cell lacks a cell wall and chloroplasts ...