What is a chromosome made of?

• A. Nucleic acids and proteins; can be condensed or uncondensed; carry genetic information
• B. Lipids and carbohydrates
• C. Only proteins
• D. Only sugars

Answer: (A)

Chromosomes are formed from DNA, a nucleic acid, bound to proteins that help package and regulate it. The DNA carries genetic information, while the associated proteins—histones and other chromosomal proteins—provide structure and allow the material to condense into visible chromosomes during cell division. So describing chromosomes as made of nucleic acids and proteins, capable of existing in condensed or uncondensed forms and carrying genetic information, is the best answer. Lipids and carbohydrates don’t form the core of chromosomes, and they aren’t made solely of proteins or sugars.