In humans, W=widows peak while w=normal hair line and A=attached earlobes while a= unattached earlobes. A heterozygote in both traits reproduces with a similar heterozygote in both traits.
What is the chance of any one child having the same genotype of the parents?
To determine the chance of any one child having the same genotype as the parents, we need to consider the principles of Mendelian genetics and the rules of inheritance for the traits in question.
In this case, we have two traits: widow's peak (W or w) and earlobes (A or a).
Let's first consider the genotype of the parents. Since both parents are heterozygous for both traits (WwAa x WwAa), we know they have the following genotypes:
Parent 1: WwAa
Parent 2: WwAa
To determine the possible genotypes of the offspring, we can use a Punnett square. A Punnett square is a graphical representation that shows all the possible combinations of alleles from the parents.
First, let's consider the widow's peak. Here, the W allele is dominant, and the w allele is recessive. So, for this trait, the genotypes and phenotypes are as follows:
WW - Widow's peak presence (homozygous dominant)
Ww - Widow's peak presence (heterozygous)
ww - No widow's peak (homozygous recessive)
Now, let's consider the earlobes. Here, the A allele is dominant, and the a allele is recessive. So, for this trait, the genotypes and phenotypes are as follows:
AA - Attached earlobes (homozygous dominant)
Aa - Attached earlobes (heterozygous)
aa - Unattached earlobes (homozygous recessive)
To create a Punnett square, we will list the possible combinations of alleles from the parents:
| Ww | Ww
_________|__________|__________
Ww | WW | Ww
_________|__________|__________
Ww | Ww | ww
In the Punnett square, we can see that there are four possible combinations of alleles for each trait. To determine the probability of any one child having the same genotype as the parents, we need to count the number of times the same genotype appears in the square.
From the Punnett square, we can see that there are three out of four combinations that have at least one allele matching the parents' genotypes. This means that the probability of any one child having the same genotype as the parents is 3/4 or 75%.
Please note that this probability assumes that the traits are independently inherited and that there are no other genetic factors influencing these traits.