Which nitrogenous bases are found in a strand of DNA?

• A. Adenine, thymine, guanine, and uracil
• B. Adenine, thymine, cytosine, and uracil
• C. Adenine, thymine, cytosine, and guanine
• D. Adenine, uracil, cytosine, and guanine

Answer: (C)

Verified step by step guidance

1. Recall that DNA is composed of four nitrogenous bases which pair specifically to form the double helix structure.
2. Identify the two categories of nitrogenous bases: purines and pyrimidines. Purines include adenine (A) and guanine (G), while pyrimidines include cytosine (C), thymine (T), and uracil (U).
3. Understand that uracil (U) is found in RNA, not DNA, so it should be excluded when listing DNA bases.
4. Recognize that the four bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
5. Confirm that adenine pairs with thymine, and cytosine pairs with guanine in DNA, reinforcing the correct set of bases.