Final answer:
The incorrect base pairing from the given options is U - T (RNA) because uracil replaces thymine in RNA and thymine is not present in RNA.
Step-by-step explanation:
The base pairings in nucleic acids, such as DNA and RNA, adhere to specific rules critical for genetic information storage and transfer. In DNA, adenine (A) consistently forms base pairs with thymine (T), while cytosine (C) pairs with guanine (G), creating complementary base pairs. However, in RNA, adenine pairs with uracil (U) instead of thymine.
The incorrect base pairing option among those listed is U - T (RNA). This is inaccurate because RNA lacks thymine; instead, it incorporates uracil. The substitution of uracil for thymine in RNA facilitates the recognition of complementary bases during processes like transcription. Understanding these base pairing rules is fundamental to decoding genetic information, as they govern the formation of the double helix structure in DNA and the single-stranded structure in RNA, ensuring the faithful transmission and expression of genetic instructions.