Which feature has major and minor grooves in the double helix?

Which feature has major and minor grooves in the double helix?

• A. DNA
• B. RNA
• C. Protein
• D. Lipid

Answer: (A)

The major and minor grooves are features of the DNA double helix. As the two strands wind around each other, the geometry of base pairing and backbone spacing creates two distinct surface indentations: a wide, major groove and a narrower, minor groove. These grooves expose different parts of the bases, providing accessible binding sites for proteins that recognize specific sequences—crucial for processes like replication, transcription, and DNA repair. RNA typically forms a different, often single-stranded or alternative helical structure, so it doesn’t present the same characteristic major/minor groove pattern. Proteins and lipids don’t form a double helix with these grooves as a defining feature, so they don’t fit this description.

The major and minor grooves are features of the DNA double helix. As the two strands wind around each other, the geometry of base pairing and backbone spacing creates two distinct surface indentations: a wide, major groove and a narrower, minor groove. These grooves expose different parts of the bases, providing accessible binding sites for proteins that recognize specific sequences—crucial for processes like replication, transcription, and DNA repair. RNA typically forms a different, often single-stranded or alternative helical structure, so it doesn’t present the same characteristic major/minor groove pattern. Proteins and lipids don’t form a double helix with these grooves as a defining feature, so they don’t fit this description.