A woman whose mother was colourblind and father was haemophilic , marries a colourblind haemophilic man . What is true about their daughters ?

Options

A. All their daughters are colourblind and haemophilic
B. They may have daughters who neither suffer from colourblindness nor from haemophilia
C. They may have daughters who are colourblind or haemophilic
D. Some of their daughters are colourblind but not haemophilic

Answer

To solve the problem, we need to analyze the genetic backgrounds of the individuals involved and determine the possible genotypes of their daughters.

### Step 1: Determine the Genotype of the Woman
The woman has a colorblind mother and a hemophilic father.

- **Colorblindness** is a recessive trait linked to the X chromosome. The genotype of a colorblind female would be **XcXc** (where Xc represents the colorblind allele).
- **Hemophilia** is also a recessive trait linked to the X chromosome. The genotype of a hemophilic male would be **XhY** (where Xh represents the hemophilia allele).

Now, let's determine the genotype of the woman:
- The mother (colorblind) contributes one X chromosome with the colorblind allele (Xc).
- The father (hemophilic) contributes either his X chromosome with the hemophilia allele (Xh) or his Y chromosome. Since the woman is female, she must have received the X chromosome from her father.

Thus, the genotype of the woman is **XcXh** (she is a carrier for hemophilia but is colorblind).

### Step 2: Determine the Genotype of the Husband
The husband is described as colorblind and hemophilic. Therefore, his genotype is:
- **XcY** (colorblind) and **XhY** (hemophilic).

Thus, the husband's genotype is **XcXhY**.

### Step 3: Cross the Genotypes to Find Daughters
Now we will cross the genotypes of the woman (XcXh) and the husband (XcY) to determine the possible genotypes of their daughters:

1. The possible combinations for daughters (XX) from the parents:
- From the woman (Xc or Xh) and the husband (Xc):
- Xc from the woman and Xc from the husband = **XcXc** (colorblind daughter)
- Xh from the woman and Xc from the husband = **XhXc** (carrier daughter, not colorblind)

### Step 4: Analyze the Results
From the cross, we find that:
- Daughters can be **XcXc** (colorblind) or **XhXc** (carrier, not colorblind).

### Conclusion
Thus, the daughters of the woman and her husband can be:
- Some of their daughters are colorblind (XcXc) and some are carriers (XhXc) but not colorblind.

### Final Answer
The correct statement is: **Some of their daughters are colorblind but not hemophilic.**