Final answer:
The assertion that base pairing is responsible only for the formation of double-stranded DNA and not RNA internal structures is false. Base pairing is fundamental in maintaining the structure of both DNA and RNA, including DNA's double helix and RNA's stem-loop configurations.The statement is false.
Step-by-step explanation:
The statement is false: Base pairing between purines and pyrimidines are responsible for forming double stranded DNA and are also crucial for the formation of internal structures such as stem-loop structures seen in RNA. In DNA, the base pairing rules are that adenine (A) pairs with thymine (T) through two hydrogen bonds, and cytosine (C) pairs with guanine (G) through three hydrogen bonds. These hydrogen bonds contribute to the stability of the DNA double helix. In RNA, however, the base thymine is replaced with uracil (U), and it pairs with adenine. The base pairing in RNA can lead to the formation of stem-loop structures which are important for the function of RNA molecules. Such structures are stabilized by the same type of hydrogen bonds as found in DNA.