Introductory Concepts

Abstract

The building blocks of all forms of life are cells. Simple organisms such as bacteria exist as single cells. Plants and animals are composed of many cell types, each organized into tissues and organs of specific functions. The determinants of genetic traits of living organisms are contained within the nucleus of each cell, in the form of a type of nucleic acids, called deoxyribonucleic acid (DNA). The genetic information in DNA is used for the synthesis of proteins unique to a cell. The ability of cells to express information coded by DNA in the form of protein molecules is achieved by a two-stage process of transcription and translation.