Following the Chromosomal Theory of Inheritance, what are the two components of the chromosome?

• A. DNA and protein
• B. RNA and protein
• C. DNA and RNA
• D. Carbohydrates and protein

Answer: (A)

The concept being tested is what the chromosome is made of. Chromosomes are complexes that consist of DNA wrapped and packaged with proteins. DNA carries the genetic information in its sequence, while proteins—especially histones and other chromosomal proteins—help package, protect, and regulate access to that DNA. The Chromosomal Theory of Inheritance linked genes to chromosomes, and the traditional view of chromosome composition was the two components: DNA and protein. This is why DNA and protein is the correct pairing. RNA isn’t considered a primary structural component of chromosomes, and pairing DNA with RNA or with carbohydrates doesn’t fit the chromosome’s typical makeup.