0845 numbers, for example, are free to call for up to an hour, during the inclusive minutes of your call package if you're a BT customer. Yet call an 0844 number and you'll be charged up to 5.1p/minute, plus a connection fee of up to 15p.
The resulting mRNA is a single-stranded copy of the gene, which next must be translated into a protein molecule. During translation, which is the second major step in gene expression, the mRNA is read according to the genetic code, which relates the DNA sequence to the amino acid sequence in proteins (Figure 2).
The process by which DNA is copied to RNA is called transcription, and that by which RNA is used to produce proteins is called translation. Each time a cell divides, each of its double strands of DNA splits into two single strands. Each of these single strands acts as a template for a new strand of complementary DNA.