Introduction to DNA and Its Significance
DNA, or deoxyribonucleic acid, is the hereditary material in all living organisms, playing a crucial role in genetics and evolution. Understanding DNA is essential for various biological concepts, especially for NEET aspirants.
Structure of DNA
- Double Helix: DNA's structure is a double helix formed by two strands of nucleotides.
- Nucleotides: Each nucleotide consists of a phosphate group, a sugar (deoxyribose), and a nitrogenous base (adenine, thymine, cytosine, or guanine).
- Base Pairing: Adenine pairs with thymine, and cytosine pairs with guanine, maintaining the structure.
Replication of DNA
- Semi-Conservative Mechanism: During replication, each strand serves as a template for a new complementary strand.
- Enzymes Involved: Key enzymes include helicase (unwinds DNA) and DNA polymerase (adds nucleotides).
Transcription and Translation
- Transcription: The process where DNA is converted into messenger RNA (mRNA) in the nucleus.
- Translation: mRNA is then translated into proteins at the ribosomes, crucial for cellular functions.
Genetic Code and Protein Synthesis
- Codons: The genetic code consists of codons, sequences of three nucleotides that specify particular amino acids.
- Start and Stop Codons: AUG is the start codon, while UAA, UAG, and UGA are stop codons.
Applications in Biotechnology
- Genetic Engineering: Techniques like CRISPR and recombinant DNA technology have revolutionized genetics.
- Medical Applications: DNA analysis is crucial for gene therapy, forensics, and understanding genetic disorders.
Conclusion
Understanding DNA is fundamental in biology, underpinning concepts from inheritance to biotechnology. Mastery of these topics is vital for success in NEET and future studies in biological sciences.

Gud