What are chromosomes composed of?

Chromosomes are primarily composed of DNA (deoxyribonucleic acid), which serves as the genetic blueprint for living organisms. Each chromosome consists of a long, tightly coiled strand of DNA that contains numerous genes, the units of heredity that encode various traits and functions within an organism. The structure of DNA enables it to store and transmit genetic information from one generation to the next, playing a crucial role in inheritance and cellular functions.

While proteins do associate with chromosomes in the form of histones and other types, their function is more about supporting the structure and regulation of DNA rather than being the primary component of chromosomes. RNA, on the other hand, plays a vital role in translating genetic information into proteins but is not part of the chromosomes themselves. Fatty acids are not related to the composition of chromosomes; they are components of lipids used for energy storage and cell membrane structure. Thus, DNA is unequivocally recognized as the fundamental building block of chromosomes.