In: Biology
**Alleles of the trait tasting are
T - ability to taste PTC (dominant allele)
t - non-taster (recessive allele)
**Genotypes and phenotypes are
a) Punnet square
Both parents are tasters who are heterozygous
Both have genotype Tt
Possible genotypes of offsprings are TT,Tt and tt
1 out of 4 children has genotype tt and they are non tasters
Probability of having non-taster child = 1/4 = 25%
b) Punnet square
One parent - non-taster (genotype - tt)
One parent - homozygous taster (genotype - TT)
Possible genotypes of offsprings is Tt only who will be taster.
Probability of having non-taster child = 0%
c)Punnet square
Both parents are non-tasters who have genotype tt
Possible genotype of offsprings is tt only. So all children will be non-tasters.
Probability of having non-taster child = 100%
d) Yes. A non-taster can have 2 biological parents that are both tasters.
This is possible when both parents are heterozygous Tt (tasters)
Then there is 25% chance of having non-taster children.
This scenario is same as question (a)