Answer:
All living things share a common code-DNA
Step-by-step explanation:
Enzymes are proteinous substances, which like every other proteins are encoded by a genes. In the expression of these genes, a set of codons (three nucleotide base) called GENETIC CODE is used. ONE of the characteristics of this genetic code is that it is NEARLY UNIVERSAL meaning that the same genetic code is used by virtually all known living organism.
According to this question, lactase enzyme, which helps digest lactose sugar in organisms, is the same in different organisms. This is due to the fact that all living things share a common code-DNA e.g AUG codes for methionine in all organisms, hence, when these DNA undergoes expression, it yields the same products in different organisms.