This chapter will concentrate on the fundamentals of molecular genetics what is DNA, how do we manipulate it and how do we analyse it to help you understand how we can achieve the incredible program of the Human Genome Project and why we are attempting it, as described in the next Chapter. Each chromosome is a single molecule of the DNA, and the 23 pairs contain all the information necessary for the fertilized egg to grow from a single cell to an adult human, and to govern the functioning of the human body. The 23 pairs of chromosomes constitute the human genome. A genome is the entire genetic information of a species. Along each chromosome are sections called genes which actually code the requisite information.
Genes can have several alternate forms called alleles.
A good example of this is in our ABO blood group.