Statement I: Purine bases present in DNA are adenine and guanine

Statement II: The base thymine is present in RNA whereas base uracil is present in DNA

Statement I is correct but Statement II is false

The correct answer is: (3) Statement I is correct, but Statement II is false.

Statement I: Purine bases present in DNA are adenine and guanine

Statement I is correct. The purine bases present in DNA are indeed adenine (A) and guanine (G). These two purine bases are essential components of DNA and are involved in base pairing with the complementary pyrimidine bases (thymine and cytosine, respectively) to form the DNA double helix.

Statement II: The base thymine is present in RNA whereas base uracil is present in DNA

Statement II is false. The base thymine (T) is present in DNA, not RNA. In DNA, thymine pairs with adenine (A) through hydrogen bonding. On the other hand, uracil (U) is present in RNA, where it pairs with adenine (A) during RNA synthesis and RNA-DNA hybridization.

Therefore, the correct answer is that Statement I is correct, but Statement II is false.