An organism's genetic information is stored in which type of macromolecule?

DNA

The macromolecule is composed of a chain of nucleotides (deoxyribose sugar and a base). Two chains, with complementary bases (G-A) and (C-T), bond to each other in the opposite direction to form DNA. They twist every base pair to form a double helix structure.

Every 3 base pair (codon) stores information for replication and translation of an amino acid (the basic unit of proteins). Sequences of these codons also code for genes.