Answer:
People with free earlobes carry one or two dominant alleles which means that the free earlobe is a dominant trait over attached earlobes that carries two recessive alleles. The recessive allele is represented by f and the dominant allele is represented by F.
It is given that in a class 25% of students in the class had free earlobes which means either 25% of total alleles are FF or Ff and the rest 75% have ff. It suggests that recessive alleles have more frequency than dominant alleles.