In humans, the curly hair gene (A) does not completely dominate the straight hair gene, and protruding ears (b)

In humans, the curly hair gene (A) does not completely dominate the straight hair gene, and protruding ears (b) are recessive. Both pairs of genes are on different chromosomes. In a family where the parents had normal ears and one with curly hair and the other straight, a child was born with protruding ears and wavy hair. Their second child had normal ears. Make a scheme for solving the problem. Determine the genotypes of the parents, their children born and the likelihood of further occurrence of children with protruding ears and wavy hair.

Since curly hair does not completely dominate straight hair, Aa is wavy hair.
If a lop-eared child was born to parents with normal ears, then they were heterozygous – Bb

A – curly hair (k)
a – straight hair (p),
Aa – wavy hair (in)
B – normal ears (n)
b – protruding ears (from)

PP F AABb * M aa Bb
k, n p, n
M / F gametes aB ab
AB AaBB – b, n AaBb – b, n

Аb АаВb – b, n Аа bb – b, from

75% children with wavy hair and normal ears
25% of children with wavy hair and protruding ears.