Which of the following includes all of the pyrimidines found in $\mathrm{RNA}$ and $\mathrm{DNA}$?

• A. $\mathrm{Thymine}$ and $\mathrm{Uracil}$
• B. $\mathrm{Cytosine}$ and $\mathrm{Uracil}$
• C. $\mathrm{Cytosine}$ and $\mathrm{Thymine}$
• D. $\mathrm{Cytosine}$, $\mathrm{Thymine}$, and $\mathrm{Uracil}$

Answer: (D)

Verified step by step guidance

1. Understand the structure of nucleic acids: DNA and RNA are composed of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base.
2. Identify the types of nitrogenous bases: There are two categories of nitrogenous bases - purines and pyrimidines. Pyrimidines have a single ring structure.
3. List the pyrimidines found in DNA and RNA: DNA contains the pyrimidines cytosine and thymine, while RNA contains cytosine and uracil.
4. Recognize the difference between DNA and RNA pyrimidines: Thymine is found in DNA but is replaced by uracil in RNA.
5. Combine the pyrimidines from both DNA and RNA: The complete list of pyrimidines found in both DNA and RNA includes cytosine, thymine, and uracil.