Question

Chickens can have different types of feathers. Frizzled feathers curl toward a chicken’s head. Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers. In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers?

Answer 1

Answer:

The percentage of the offspring that can be expected to have frizzled feathers is either $100$% or $75$%

Explanation:

Having frizzled feathers is a dominant trait in chickens  and let it be represented by "F"

Having straight hair is a recessive trait in humans , and let it be represented by "f"

When a dominant and recessive trait occur together, only the trait associated with the dominant allele is expressed and a recessive trait is expressed when both the cell has both  the recessive traits alleles.

Now  a cross is carried between two parents having frizzled hair , the following two cases may arise

case I - When both the parents are dominant homozygous, which means

Father Chicken has genotype "FF"

Mother Chicken has genotype "FF"

The following offsprings are produced as per the punnet square given below -

        F  F

F FF FF

F FF FF

All the offspring will be having frizzled hair.

Therefore the percentage of the offspring that can be expected to have frizzled feathers is $\frac{4}{4} * 100\\= 100$ %

Case II - When both the parents are dominant heterozygous, which means

Father Chicken has genotype "F"

Mother Chicken has genotype "Ff"

The following offsprings are produced as per the punnet square given below -

      F  f

F FF Ff

f Ff ff

Out of 4 offspring, three have frizzled hairs i.e FF, Ff, Ff

Therefore the percentage of the offspring that can be expected to have frizzled feathers is $\frac{3}{4} * 100\\= 75$ %

The percentage of the offspring that can be expected to have frizzled feathers is either $100$% or $75$%

Answer 2

Question : what percentage of the offspring can be expected to have frizzled feathers?



Answer : 0%