On human genome project and how genome is changing in future [I]

　　The human genome project (HGP), the manhattan A-bom b project and the apollo landing-moon project are three gigantic enginerring systems enjoying equal fame in nat ural science history. However, the influence of the HGP on human beings themselves will exceed that of the othe r two projects greatly.

　　Genes are the most basic factors of biological spec ies. Species are decided by their genetic information, and the carriers of the genetic information are deoxyri bonucleic acid(DNA). DNA is the substance of genes. Hum an genetic matter is also DNA, whose total is human gen ome(基因组). It is estimated that there are 100 thousand g enes, consisting of about 3 billions base pairs distrib uted in 23 pairs of chromosome(染色体) (46 chromosomes) of cell nucleus in human body. Half of the chromosome come from mother, and the otherhalf from mother . such a lit tle stick-like thing is composed of a DNA molecule. Its chemical construction is two paralleled chains twisted together. If they are pulled straight, it will be like a ladder, of which every rung is made up of nucleotide( 核苷酸). Nucleotide can be divided into 4 knids. They are called A,G, C and T and short respectively according to the composition of their base pairs. If in a certain ru ng of the ladder there exists a heredity effect, it's c alled gene. That is to say, gene is a segment of DNA an d may be either very long or very short. The HGP aims a t measuring and ascertaining the genes sequence of whol e human genome. This gene sequence is as illegible a te n million pages book of life written by angles from hea ven.

　　To be continued

　　By zhang zhiming, ha' erbin