Answer:
Four different types of nitrogenous bases are found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G).
Step-by-step explanation:
DNA is a polynucleotide. Each nucleotide is made up of deoxyribose sugar, a phosphate group and nitrogenous base. In DNA, there are four main kinds of nitrogenous bases. Adenine (A), guanine (G), thymine (T), and cytosine (C) are the four bases of DNA (C). Purine bases are adenine and guanine, whereas pyrimidine bases are thymine and cytosine. Base pairing occurs between complementary bases on two strands of double-stranded DNA. By two and three hydrogen bonds, A and G link with T and C, respectively. In RNA, uracil is present instead of thymine.