Answer:
Father's genotype is T T, E e
Mother's genotype is t t, E e
Explanation:
Tasting PTC
Let the characters for tasting and not tasting PTC be T and t respectively.
Since all the children can taste PTC, it can be deduced that tasting PTC is a dominant trait.
The man will be homo-zygous dominant for tasting PTC while the woman is homo-zygous recessive for tasting PTC.
Genotype of man is T T and genotype of woman is t t
T T x t t = T t, , T t, T t; which is a 4:0 phenotype.
Earlobes:
Let the characters for Free and attached earlobes be E and e
Since both the man and woman have free earlobes and 3 out of 4 children have free earlobes, it can be deduced that free earlobes is dominant while attached earlobes is recessive.
The ratio of free to attached earlobes is 3:1
The man and the woman are both hetero-zygous dominant, E e for free earlobes, so that a cross between them will yield three hetero-zygous dominant for free earlobes and one homo-zygous recessive for attached earlobes.
E e x E e = E E, E e, E e, e e; which is a 3 : 1 phenotype.
