DNA function

DAN is a polymer of Deoxyribonucleotides which is the chemical basis of  heredity  regarding as the reserve bank of genetic information that may be carried out from generation to generation .DNA  is exclusively responsible for maintaining the identity of different species of organism over million of years retaining the characteristic of fore-Father . Actually DNA is the functional precursor for every aspects of cellular function by organizing into genes,the essential unit of genetic information.

DNA perform three essential function-----

v      The genotypic function-------

The genetic material must store genetic information and accurately transmit that information from parents to offspring, generation after generation.

v      The phenotypic function----

DNA controls the development of the phenotype of the organism. That is, the genetic material must dictate the growth and differentiation of the organism from the single- celled zygote to the mature adult.

v      The evolutionary function  ----------------------------

The genetic material must undergo change so that organisms can adapt to modification in the environment. Without those changes, evaluation could not occur.

DNA provides a template for transcription of the approximately 100000 genes that encode a variety of RNA molecules.

Other early genetic studies established a precise correlation between the patterns of transmission of genes as well as the behavior of chromosomes during sexual reproduction, providing strong evidence that genes are usually located on chromosomes .hus further attempts to discover the chemical basis of heredity focused on molecules present in chromosomes.

 

PROCEDURE OF THE STORAGE OF GENETIC MATERIALS

Several lines of indirect evidence suggested that DNA harbors the genetic information of living organisms.

1.       Maximum DNA of cells is located in the chromosomes, whereas RNA and proteins are also abundant in the cytoplasm.

2.       A precise correlation exists between the amount of DNA per cell and the number of sets of chromosomes per cell. For example, most somatic cells of diploid organisms contain twice the amount of DNA as the haploid germ cells (gametes) of the same species.

3.       The, molecular composition of the DNA is the same (with rare exceptions) in all the different cells of an organism, whereas the composition of both RNA and proteins is highly variable from one cell type to another.

4.       DNA is more stable than RNA or proteins, which are synthesized and degraded quite rapidly in living organisms. Since the genetic material must store and transmit information from parents to off spring, we might expect it to be stable, like DNA.

 PROCEDURE OF TRANSFERRING OF GENETIC INFORMATION

According to the central dogma of molecular biology, genetic information flows (1) from DNA to DNA during its transmission from generation to generation and (2) from DNA to protein during its phenotypic expression is an organism. The transfer of genetic information from DNA to protein involves two steps

1) transcription, the retransfer of the genetic material from DNA to RNA, and

(2) translation, the transmission of information from RNA to protein.

In addition, genetic material flows from RNA to DNA through the conversion of the genomes of RNA tumor viruses to their DNA proviral forms. Thus the transfer of genetic material from DNA to RNA is sometimes reversible, whereas the transmission of information from RNA to protein is always irreversible.
Ethics and law