Answer:
0.25
Explanation:
A man who is a taster and has a non-taster mother can only be heterozygous (Tt) for the trait since his mom is homozygous recessive (tt).
A man who is a taster marries a woman who is a taster with five siblings, three of whom are non-tasters. Thus the woman can be said to be to be heterozygous. This is because, for her parents to be able to produce her non- tasters siblings, both have to have one copy each of the recessive allele (t) and since she is a taster (T), it means one or both of her parents possess one copy of the dominant trait (T). This accounts for her being an heterozygote (Tt).
the man who is Tt marries a woman who is also Tt. Chances that the children of this marriage will be non-tasters will be 1/2 x 1/2 = 1/4 = 0.25