DNA

DNA, or deoxyribonucleic acid, is a molecule that plays a fundamental role in the molecular basis of inheritance. It is often referred to as the “genetic blueprint” or the “molecule of life” because it carries the genetic information necessary for the growth, development, and functioning of all living organisms. In this introduction, we will explore the structure, function, and significance of DNA in the context of molecular inheritance.

Structure of DNA:

DNA has a double-helix structure, which was first elucidated by James Watson and Francis Crick in 1953. This structure consists of two long chains, or strands, of nucleotides running in opposite directions and coiled around a central axis. Each nucleotide consists of three components:

1. Deoxyribose Sugar: A five-carbon sugar molecule, known as deoxyribose, forms the backbone of the DNA strand.

2. Phosphate Group: Attached to the deoxyribose sugar are phosphate groups, which provide a negative charge to the DNA molecule.

3. Nitrogenous Bases: Four different nitrogenous bases are found in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). These bases pair up in a complementary manner: A with T and C with G. This base-pairing forms the rungs of the DNA ladder.

The complementary base-pairing allows DNA to replicate accurately during cell division, ensuring that each daughter cell receives an identical copy of the genetic information.