Hypophoshatemia (vitamin D-resistant rickets) is inherited as an x-linked dominant trait. What is the expected outcome of a cross between a homozygous recessive woman and a man with hypophoshatemia?

### All of their daughters and none of their sons exhibit hypophosphatemia.

## Step1: Understanding the Genetics### Hypophosphatemia is an x-linked dominant trait. This means that the gene causing the trait or the disorder is located on the X chromosome. Females have two X chromosomes, so they can be either homozygous dominant (having two copies of the dominant gene) or homozygous recessive (having two copies of the recessive gene). Males, on the other hand, have one X and one Y chromosome, so they can only be either homozygous dominant or homozygous recessive.## Step2: Analyzing the Cross### In this case, the woman is homozygous recessive, meaning she has two copies of the recessive gene on her X chromosomes. The man has hypophosphatemia, which is an x-linked dominant trait, meaning he has the dominant gene on his X chromosome. When they have children, each child gets one X chromosome from the mother and one X chromosome from the father.## Step3: Predicting the Outcome### All daughters will receive one X chromosome from the mother (with the recessive gene) and one X chromosome from the father (with the dominant gene for hypophosphatemia). Therefore, all daughters will be heterozygous and will exhibit hypophosphatemia. Sons, on the other hand, will receive an X chromosome from the mother (with the recessive gene) and a Y chromosome from the father. Therefore, none of the sons will receive the dominant gene for hypophosphatemia and they will not exhibit the trait.