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 offspring’s. Thus, DNA is called as molecular blueprint or thread of life.

2. Autocatalytic role DNA:

DNA undergoes replication (self-duplication) 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. Hetero-catalytic role:

During transcription any one strand of DNA acts as template for the synthesis of RNA. This is called the hetero-catalytic role of RNA.

4. Variations:

DNA undergoes recombination at meiosis and occasional mutation (changes in nucleotide sequences) which creates variations in population and ultimately contributes to evolution.

5. DNA controls cellular metabolism, growth, and differentiation.

6. DNA finger printing (=DNA typing or profiling):

Each individual carries specific short nucleotide repeats which are called as mini-satellites or VNTRs (Variable Number of Tandem Repeats). The 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 (Genetic engineering):

It involves the artificial cleaving and rejoining DNA sequences from two or more organisms to create recombinant DNA. This technology is employed for production of genetically modified organisms (GMOs), genetically modified foods (GMFs), vaccines, hormones, enzymes, clones etc. It is also used for construction of probes (short polynucleotide chain attached to a radioactive or fluorescent marker) for diagnosis of diseases and curing hereditary diseases by replacing a faulty gene with a normal gene (gene therapy), formation of clones etc.