Final answer:
The complementary sequence to the DNA strand GCAGTAG is CGTCACT, according to base pairing rules of DNA where A pairs with T and G pairs with C.
Step-by-step explanation:
DNA serves as the molecular basis for life and has a double helix structure composed of nucleotides. The sequence of the opposite strand that complements the DNA strand with the sequence GCAGTAG would be formed by pairing each nucleotide with its complementary base, following the base pairing rules: adenine (A) with thymine (T), and guanine (G) with cytosine (C).
Therefore, the sequence of the opposite strand is CGTCACT. The sequence of nucleotides in DNA determines the genetic information, and it is through the processes of transcription and translation that RNA and proteins are synthesized, respectively.