Answer
Fig. 18.13 shows that a gene can produce different proteins depending on which of its many exons are used to produce that protein-- not all are used for all proteins from the same gene. Thus, one gene can produce different proteins (different overall sequences) with different functions in different tissues.
Work Step by Step
This reviews the idea, repeatedly stated in earlier chapters, that one gene can produce multiple proteins via differential splicing of mRNA. That means proteins with different overall sequences, and sequence determines function. Thus, multiple protein functions from one gene as it is expressed at different times in different places in an organism.