Final answer:
The complement of adenine in DNA is thymine, and this pairing is due to the specific hydrogen bonding between these bases, which is essential to the structure and replication of DNA.
Step-by-step explanation:
The complement of adenine in DNA is thymine. Adenine (A) pairs with thymine (T) through two hydrogen bonds in the DNA double helix. These nitrogenous bases adhere to Chargaff's rules, indicating that the amount of adenine and thymine is equal to the amount of guanine and cytosine in a DNA molecule. This base pairing is crucial to the structure and function of DNA, as it enables accurate replication during cell division and maintains a consistent genetic code across different species. The complementary base pairs between purines and pyrimidines, such as adenine and thymine, have a similar shape and structure, enabling the double helix to have a uniform diameter.
The role of complementary base pairing in DNA structure and replication is fundamental to the understanding of genetic inheritance and molecular biology. These base pairings are specific – adenine always pairs with thymine, and cytosine always pairs with guanine, maintaining the overall structure of DNA.