For two chemicals like starch and cellulose to be made using the same enzymes, they would have to have similar structure. However, starch and cellulose, though both composed of glucose, involve different bonds. Therefore, the same enzymes would probably not be involved in making both starch and cellulose.
Work Step by Step
To answer this, first consider what allows an enzyme to do its job--its shape (and that of what it is making). Then consider he shape of the two putative products of the same enzyme (starch and cellulose). The book makes it clear that they have very distinct shapes, which would probably require very distinct enzymes for their production.