Figure 1 represents pаrt оf а prоcess essentiаl tо gene expression. The two strands of the helix are paired at each end but are separated in the central portion. Bases of the nucleotides are indicated for the entire length of each strand. The left end of the upper strand is labeled 5 prime, and the right end is labeled 3 prime. The left end of the lower strand is labeled 3 prime, and the right end is labeled 5 prime. The lower strand is also labeled Strand X. An additional single strand of nucleotides that is complementary to the lower DNA strand is also present on the left and central portions of the figure. The sequence of the strand, from the left 5 prime end to the right 3 prime end, is as follows: A U G C C G C A A U C U G U U C A C G C A C U C A U G U G. Above the strand an arrow labeled Direction of Synthesis points along the strand from left to right. Figure 1. Model of process involved in gene expression. Which of the following best explains what strand X represents?