Answer:
why two brothers might have different kinds of earwax is:
B. They have different alleles for a particular gene.
Step-by-step explanation:
The type of earwax a person has is determined by their genetic makeup, specifically by the alleles they inherit for a specific gene related to earwax consistency. Alleles are different forms or variations of a gene. In the case of earwax, there is a gene involved that can have two different alleles, one associated with wet earwax and the other with dry earwax. If two brothers inherit different alleles for this gene from their parents, it can result in each of them having a different type of earwax, either wet or dry. The presence of different alleles is the underlying reason for the variation observed in their earwax consistency.