Hereditary (from the Latin hereditarius , meaning "to inherit") is the biological process by which a parent transmits specific physical, physiological, or even behavioral traits to their offspring. It is the fundamental mechanism that ensures the continuity of species while simultaneously allowing for the diversity that makes evolution possible.
At its core, heredity explains why children look like their parents, why certain diseases run in families, and why a puppy grows into a dog rather than a cat. It is the passage of genetic information—the instruction manual for building and operating an organism. The physical vehicle of heredity is Deoxyribonucleic acid (DNA) . DNA is a long, double-stranded molecule shaped like a twisted ladder (a double helix). Segments of this DNA that code for specific traits—like eye color, blood type, or the shape of a leaf—are called genes .
