Thalassemia is controlled by ______ genes preset on ______ chromosome.

Options

A. one, 16
B. two, 11
C. two, 16
D. three, 11

Answer

To answer the question regarding thalassemia, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Thalassemia**:
- Thalassemia is a genetic blood disorder that affects the production of hemoglobin, the protein in red blood cells that carries oxygen.

2. **Identifying the Genes Involved**:
- Thalassemia involves two types of globin chains: alpha and beta chains.
- The alpha globin chain is controlled by two genes, while the beta globin chain is controlled by one gene.

3. **Locating the Chromosomes**:
- The genes responsible for the alpha globin chain are located on chromosome 16.
- The gene responsible for the beta globin chain is located on chromosome 11.

4. **Determining the Correct Answer**:
- The question asks how many genes control thalassemia and on which chromosomes they are located.
- Since there are two genes on chromosome 16 (for the alpha chain) and one gene on chromosome 11 (for the beta chain), the correct answer is:
- Thalassemia is controlled by **two genes** present on **chromosome 16** (for the alpha chain) and **one gene** on **chromosome 11** (for the beta chain).

5. **Final Answer**:
- Therefore, the answer to the question is: **Thalassemia is controlled by 2 genes present on chromosome 16 and 1 gene present on chromosome 11**.