Which term refers to deoxyribonucleic acid, the self-replicating material that is the main constituent of chromosomes in nearly all living organisms?

• A. RNA
• B. DNA
• C. Nucleic Acid
• D. Protein

Answer: (B)

DNA is the molecule that stores genetic information and forms the main material of chromosomes in nearly all living organisms. It stands for deoxyribonucleic acid, and its ability to self-replicate during cell division lets genetic information be accurately passed to new cells. The double-helix structure and the specific base pairing (A with T, C with G) make this copying precise, which is essential for inheritance and proper development. RNA, by contrast, is another nucleic acid involved mainly in directing protein synthesis and regulation; it is usually single-stranded and not the principal genetic material in most organisms. Nucleic acid is the broad category that includes both DNA and RNA, while protein is a different type of molecule made from amino acids that does not store genetic information.