Final answer:
During DNA transcription, only one strand of RNA is transcribed from the template strand of the DNA. The other DNA strand, the coding strand, is not transcribed but serves as a reference sequence.
Step-by-step explanation:
DNA transcription involves creating one strand of RNA from the DNA template. When DNA unzips, it forms what's known as a transcription bubble, where the enzyme RNA polymerase synthesizes RNA. During this process, only one of the DNA strands, called the template strand, is used for transcription. The other strand, known as the coding strand, is not transcribed; instead, it has the same sequence as the resulting mRNA except for thymine (T) being replaced by uracil (U) in RNA.