Sickle cell anaemia is favoured by nature in a malaria - prone area. Which of the following category will be favoured and what type of selection is it?

Options

A. Normal individual , balancing selection
B. Homozygous individual sickle cell, disruptive selection
C. Heterozygous female, balancing selection
D. Homozygous male, normalising selection

Answer

To solve the question regarding sickle cell anemia and its relationship with malaria, we will analyze the options provided and determine which category is favored and the type of selection involved.

### Step-by-Step Solution:

1. **Understanding Sickle Cell Anemia**:
- Sickle cell anemia is a genetic condition where red blood cells (RBCs) become sickle-shaped due to the presence of an abnormal hemoglobin gene. This condition can lead to various health complications.

2. **Heterozygous Advantage**:
- Individuals who are heterozygous for the sickle cell trait (having one normal hemoglobin gene and one sickle cell gene) have a protective advantage against malaria. This means that they are less likely to suffer severe effects from malaria compared to those who are homozygous for normal hemoglobin or homozygous for sickle hemoglobin.

3. **Evaluating the Options**:
- **Option 1**: Normal individual and balancing selection - Incorrect. Normal individuals do not have the protective advantage against malaria.
- **Option 2**: Homozygous individual sickle cell and disruptive selection - Incorrect. Homozygous individuals with sickle cell anemia suffer from severe health issues and do not have the protective advantage.
- **Option 3**: Heterozygous female and balancing selection - Correct. Heterozygous individuals are favored in malaria-prone areas due to their resistance to malaria, and balancing selection helps maintain both alleles in the population.
- **Option 4**: Homozygous male and normalizing selection - Incorrect. Similar to option 2, homozygous individuals do not benefit from the protective advantage.

4. **Conclusion**:
- The favored category in malaria-prone areas is **heterozygous individuals**, and the type of selection is **balancing selection**. This selection maintains the presence of both alleles in the population due to the survival advantage provided to heterozygous individuals against malaria.

### Final Answer:
- **Favored Category**: Heterozygous individuals
- **Type of Selection**: Balancing selection