Which bases are part of the DNA structure?

• A. Adenine, Uracil, Cytosine, Guanine
• B. Adenine, Thymine, Guanine, Cytosine
• C. Adenine, Thymine, Uracil, Cytosine
• D. Adenine, Thymine, Cytosine, Ribose

Answer: (B)

The correct answer identifies the bases that are fundamental components of DNA. In DNA, the bases are specifically adenine, thymine, guanine, and cytosine. These bases pair in a specific manner—adenine pairs with thymine, and guanine pairs with cytosine—forming the rungs of the DNA double helix.

This pairing is crucial for maintaining the stability of the DNA structure and for proper replication during cellular division. Each base contributes to the genetic code, with sequences of these bases providing the instructions for synthesizing proteins, which are essential for various cellular functions.

The presence of uracil in the other options distinguishes RNA from DNA, as uracil replaces thymine in RNA structures. Similarly, options that include ribose refer to the sugar component in RNA, while DNA contains deoxyribose. It’s important to recognize the unique components that differentiate DNA from RNA to fully understand the structural significance and functional roles of nucleotides in both nucleic acids.