1. DNA (Deoxyribonucleic acid): This is the genetic material that carries the instructions for building and maintaining an organism. It's arranged in a long, linear molecule and is wound tightly around proteins called histones.

2. Proteins (Histones): These proteins help to package and organize the DNA into a compact structure, allowing it to fit within the nucleus of a cell. They also play a role in regulating gene expression.

Together, the DNA and associated proteins form a chromosome, which is essentially a highly organized structure that contains the organism's genetic information.