A student is completing a Punnett square for a trait (X/x) that is autosomal and inherited by the dominant allele. The father does not have it (xx), but the mother does (Xx). If they had two children, a son and a daughter, what would the completed Punnett square look like (i.e., would the son have the trait, would the daughter have the trait)? (1 point)
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• One child would inherit the trait and one child would not.
•Both children would inherit the trait.
Each child has a 50% chance of inheriting the trait.
Both children would not inherit the trait
To determine the possible outcomes of a trait inherited through the dominant allele in an autosomal manner, we can use a Punnett square.
First, let's designate the alleles for the trait. The dominant allele is represented by a capital letter (X), and the recessive allele (lack of the trait) is represented by a lowercase letter (x).
According to the given information, the father does not have the trait (xx), while the mother is heterozygous for the trait (Xx).
To create a Punnett square, we need to list the possible gametes (sperm and eggs) for each parent. Since the father does not have the trait, he can only contribute an x allele. The mother, being Xx, can contribute either an X or an x allele.
The Punnett square for this scenario would look like this:
| X | x |
---------------------
X | XX | Xx |
---------------------
x | xX | xx |
Now, we can determine the possible genotypes of the children.
Starting with the first child, a son:
The son would inherit one allele from each parent. Let's follow the row for the mother (Xx) and the column for the father (xx). The possible combinations for the son are XX and xx.
For the second child, a daughter:
Again, she would inherit one allele from each parent. Following the same row for the mother (Xx) and the column for the father (xx), the possible combinations for the daughter are Xx and xx.
Now, let's determine whether the children would have the trait:
We know that the trait is autosomal and inherited through the dominant allele. Therefore, if a child has at least one X allele, he or she will express the trait. Conversely, if a child has two x alleles, he or she will not have the trait.
Applying this knowledge to the Punnett square:
The son's potential genotypes are XX (trait) and xx (no trait). Therefore, one child would inherit the trait (Xx).
The daughter's potential genotypes are Xx (trait) and xx (no trait). Therefore, one child would also inherit the trait (Xx).
To summarize, based on the Punnett square, both the son and the daughter would have a 50% chance of inheriting the trait.