Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

In the given pedigree diagram, the parents are having free ear-lobe structure. Out of their 5 kids (2 boys and 3 girls), one boy and one girl have attached ear lobe and other 3 have free ear lobe. Since there is expression of attached earlobe in the next generation, even though parents are not having it, the free earlobe allele is dominant over the attached ear lobe. It can be concluded that the parents are not homozygous for free ear lobe. Also, it is not Y-linked as it is expressed in both male (XY) and female (XX) of next generation.