DNA has set of coded instructions required by all organisms for specific traits.

DNA provides way of passing on traits.

Heredity= the passage of traits from one generation to the next.

DNA characteristics: double stranded molecule, twisted ladder = alpha helix

-sides of the ladder have alternating phosphate and deoxyribose sugar units

-rungs of the ladder are pairs of nitrogenous bases

-bases = A- adenine, T- thymine, G-guanine, C- cytosine

-pairing of bases: A-T, G-C = complementary base pairing (G CAT)