In the pedigree given below, indicate whether the shaded symbols indicate dominant or recessive allele. Also give genotype of the whole pedigree.

Explanation

Since the shaded symbot appears in all the offsprings , father must be homozygous dominant while the mother homozygous recessive (AA `xx` aa = all Aa) because in all other cases this possibility is absent (`Aa xx aa = 2Aa + 2aa, aa xx AA` = all `Aa , aa xx Aa = 2aA + 2aa`), All the members of II generation will, therefore be heterozygous (Aa). This is further confirmed by marriage of II 1 with homozygous recessive `(Aa xx aa = 2Aa, 2aa)` and bearing chlidren of both the parental types. Marriage of II -3 with the homozygous recessive can produce both recessive and heterozygotes as are present here.