Mnemonic for pyrimidines?

• A. CUT the PY
• B. A and C
• C. Pyrimidines are two rings
• D. Purines are single rings

Answer: (A)

The main idea here is how to memorize which bases are pyrimidines. Pyrimidines are single-ring nitrogenous bases, and the bases that belong to this group are cytosine, uracil, and thymine. The mnemonic “CUT the PY” directly captures those three bases (C, U, T) and signals they’re pyrimidines with the “PY” at the end. It’s simple, memorable, and accurate, which is why it’s the best choice.

The other statements conflict with what pyrimidines are or with the known base classifications: pyrimidines are not two-ring structures, and purines are not single-ring; that makes the alternatives incorrect.