in humans, normal people are dominant (X) to people with x-ray vision. If a mutant with x-ray vision has a child with a woman heterozygous for x-ray vision what is the chance that one of their children will have x-ray vision?

2/4 or 50%

Explanation:

Heterozygous means the organism has two different alleles, so the genotype of the woman is Xx

The mutant's genotype is xx, because in order for a recessive trait to be expressed, there needs to be two recessive alles

Use the genotypes of the parents to create a punnett square (shown in image) to find the possible genotypes of their children

To chance of a phenotype is determined by how many of the possible genotypes will express the phenotype of x-ray vision and how many genotypes there are in total. The chance can be presented like this:

2/4

2 is the number of x-ray children

4 is the total number of children

To find the percentage you can do 2 ÷ 4 × 100

And that will give you the answer of 50

So the percentage is 50%