How many polypeptide chains are present in gamma immunoglobulin
or
How many variable segments are present in the basic structure of antibody molecule

Options

A. 6
B. 2
C. 7
D. 4

Answer

To answer the question regarding the number of polypeptide chains in gamma immunoglobulin and the number of variable segments in the basic structure of an antibody molecule, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Antibody Structure**:
Antibodies, also known as immunoglobulins, are Y-shaped molecules composed of polypeptide chains. Each antibody consists of two types of chains: heavy chains and light chains.

2. **Identifying the Chains in Gamma Immunoglobulin**:
In the case of gamma immunoglobulin (IgG), it is made up of 4 polypeptide chains in total. This includes:
- 2 heavy chains
- 2 light chains

3. **Determining the Variable Segments**:
Each antibody molecule has variable regions that are crucial for its ability to bind to specific antigens.
- The variable segments are located at the tips of the Y-shaped structure.
- There are 2 variable regions on the heavy chains and 2 variable regions on the light chains.

4. **Calculating Total Variable Segments**:
Therefore, the total number of variable segments in a gamma immunoglobulin is:
- 2 (from heavy chains) + 2 (from light chains) = 4 variable segments.

5. **Conclusion**:
Thus, the answer to the question is that gamma immunoglobulin has 4 variable segments in its basic structure.

### Final Answer:
There are 4 variable segments present in the basic structure of the gamma immunoglobulin antibody molecule.

---