Which component is found in DNA but not RNA?

• A. Thymine
• B. Uracil
• C. Phosphate group
• D. Ribose

Answer: (A)

Verified step by step guidance

1. Recall the four nitrogenous bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G).
2. Recall the four nitrogenous bases found in RNA: adenine (A), uracil (U), cytosine (C), and guanine (G).
3. Compare the bases in DNA and RNA to identify which base is unique to DNA and which is unique to RNA.
4. Note that thymine is present in DNA but replaced by uracil in RNA.
5. Recognize that phosphate groups and sugar components (deoxyribose in DNA and ribose in RNA) are present in both molecules, so they are not unique to DNA.