Final answer:
Chargaff's rules apply to the complementary base pairing in DNA, where A pairs with T and G with C. However, in RNA, A pairs with U (uracil) and it is single-stranded, thus Chargaff's rules do not apply in the same way. Therefore, it is false that both DNA and RNA follow Chargaff's rules of base pairing exactly the same way.
Step-by-step explanation:
Chargaff's rules state that in DNA, adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C). This is due to the complementary base pairing where purines always pair with pyrimidines, forming hydrogen bonds between them. Chargaff discovered that the amount of A is similar to the amount of T, and the amount of G is similar to the amount of C. Watson and Crick based their model of DNA on these observations, noting that the two strands of the DNA double helix are antiparallel and complementary to each other, which provides a stable structure for the molecule.
However, Chargaff's rules do not apply to RNA in the same way because RNA contains uracil (U) instead of thymine, and it is typically single-stranded rather than double-stranded. Therefore, the base pairing in RNA usually occurs within a single strand, forming secondary structures. In RNA, adenine pairs with uracil (A=U) and guanine still pairs with cytosine (G=C).
False, the correct answer is that both DNA and RNA do not follow Chargaff's rules of base pairing exactly the same way—RNA has a different base (uracil instead of thymine) and can form various structures, not just a double helix. For the DNA sequence ATTG, its complementary sequence is TAAC, with A pairing with T and G with C.