The correct answer is:
A. Base, sugar ring, and phosphate
Explanation:
1. A nucleotide is the basic building block of nucleic acids like DNA and RNA.
2. It consists of three main components:
- Base: The nitrogenous base (adenine, thymine, cytosine, guanine, or uracil in RNA) that pairs with another base in DNA or RNA.
- Sugar ring: A five-carbon sugar molecule (deoxyribose in DNA or ribose in RNA) that forms the backbone of the nucleic acid strand.
- Phosphate group: A phosphorus atom bound to four oxygen atoms, linking the nucleotides together in a chain.
3. The combination of a nitrogenous base, sugar molecule, and phosphate group forms a nucleotide, which then joins with other nucleotides to create DNA or RNA molecules.
This structure of a nucleotide is crucial for the genetic information storage and transfer processes within living organisms.
