BIOLOGICAL IMPORTANCE OF DNA
- 1. HEREDITARY MATERIAL The genetic information stored in the nucleotide sequence of DNA helps in synthesis of specific proteins or polypeptides and transmit the information to daughter cells or off -springs. Thus DNA is called as molecular blueprint or thread of life.
- 2. AUTOCATALYTIC ROLE DNA DNA undergoes replication in the S-phase of cell cycle. During the process each DNA strand of a double helix can act as template for the synthesis of daughter strand.
- 3. HETEROCATALYTIC ROLE During transcription any one strand of DNA acts as template for the synthesis of RNA. This is called the heterocatalytic role of RNA.
- 4. VARIATIONS DNA undergoes recombination at meiosis and occasional mutation which creates variations in population and ultimately contributes to evolution.
- 5. DNA CONTROLS CELLULAR METABOLISM,GROWTH AND DIFFERENTIATION.
- 6. DNA FINGER PRINTING Each individual carries specific short nucleotide repeats which are called as minisatellites or VNTRs(variable number of tandem repeats.) this VNTRs of two individuals are variable and forms the basis of DNA fingerprinting. This technique is used to identify criminals , determine paternity, verification of immigrant etc.
- 7. RECOMBINANT DNA TECHNOLOGY. It involves the artificial cleaving and rejoining DNA sequences from two or more organisms to create rDNA. It is also used for construction of probes for diagnosis of diseases and curing hereditary diseases by replacing a faulty gene with a normal gene.(gene therapy) and formation of clones etc.