Read the passage given below and answer the following 5 questions.
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two types of nucleic acids found in living systems. DNA acts as the genetic material in most of the organisms. RNA though it also acts as a genetic material in some viruses, mostly functions as a messenger. RNA has additional roles as well. It functions as adapter, structural, and in some cases as a catalytic molecule.The chemical structure of a polynucleotide chain (DNA or RNA). A nucleotide has three components – a nitrogenous base, a pentose sugar (ribose in case of RNA, and deoxyribose for DNA), and a phosphate group. There are two types of nitrogenous bases – Purines and Pyrimidines . .

Which of the following purine and pyrimidine are present in DNA? (Question 1)

Adenine and Thymine

The correct answer is option (1) - Adenine and Thymine

In DNA, the purine bases are adenine (A) and guanine (G) the same as in RNA, and the pyrimidine bases are cytosine (C) and thymine (T) , in RNA, they are cytosine and uracil. Purines are larger than pyrimidines because they have a two-ring structure while pyrimidines only have a single ring. The base-pairing rule in DNA is specific: Adenine always pairs with Thymine, and Guanine always pairs with Cytosine. This complementary base pairing is a key feature of the DNA double helix structure.