Fetal haemoglobin has X affinity for oxygen than that of mother's haemoglobin during gestation. X is

Options

A. same
B. higher
C. lower
D. lower affinity earlier but higher later.

Explanation

To solve the question regarding the affinity of fetal hemoglobin for oxygen compared to that of the mother's hemoglobin during gestation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hemoglobin Function**:
- Hemoglobin is a protein in red blood cells responsible for transporting oxygen from the lungs to the body's tissues and returning carbon dioxide from the tissues back to the lungs.

2. **Identifying Fetal Hemoglobin**:
- Fetal hemoglobin (HbF) is the type of hemoglobin found in the fetus. It is different from adult hemoglobin (HbA) in its structure and function.

3. **Comparing Affinity for Oxygen**:
- The key aspect of this question is the affinity of fetal hemoglobin for oxygen compared to maternal hemoglobin. Affinity refers to how strongly hemoglobin binds to oxygen.

4. **Reason for Higher Affinity**:
- Fetal hemoglobin has a higher affinity for oxygen than maternal hemoglobin. This is crucial because the fetus relies on extracting oxygen from the mother's blood supply. A higher affinity allows the fetus to effectively take up oxygen even when the oxygen concentration is lower in the maternal blood.

5. **Conclusion**:
- Therefore, we conclude that the value of X, which describes the affinity of fetal hemoglobin for oxygen compared to that of the mother's hemoglobin, is "higher".

### Final Answer:
X is higher.