The Clue The "A" of DNA
The Answer ACID
The "A" in DNA stands for adenine, which is one of the four building blocks of DNA. DNA is made up of nucleotides, and each nucleotide includes a sugar, a phosphate group, and a nitrogenous base. Adenine is classified as a type of acid, specifically a nucleic acid, which is why "acid" fits the crossword clue. Understanding this helps connect the letters in DNA to their scientific meanings.