**Antibody Structure and Function**The diagram illustrates the different regions of an antibody. This particular image is used to identify which part of the antibody binds to an antigen and explain its significance.**Diagram Explanation:**1. **Region 1:** Represents the part of the antigen to which the antibody binds.2. **Region 2:** The stem of the Y-shaped antibody known as the Fc region. It interacts with cell receptors and complement proteins.3. **Region 3:** The hinge region allows for flexibility, enabling the antibody to adapt to the distance between epitopes.4. **Region 4:** The light chain variable region responsible for binding antigens.5. **Region 5:** The antigen-binding site, composed of both heavy and light chain regions to recognize and attach specifically to antigens.**Multiple-Choice Explanation:**- **Option 1:** Incorrect. Antibodies do not generate antibiotics.- **Option 3:** Reflects flexibility but not direct antigen binding.- **Option 4:** Indicates dimerization or complex formation, not primary antigen binding.- **Option 5:** Correct. This region allows the antibody's specific recognition of an antigen.In antibodies, the antigen-binding site (Region 5) is crucial for immune specificity and the subsequent immune response.

Antibodies: When any foreign substances enter the body they are eliminated from the body with the help of protein molecules or immunoglobin molecules produced by the immune system of the body. The molecules are called antibodies. Antibodies are specifically produced by the B cells of the immune system and help fight the antigenic substances inside the body. From the given diagram the region that binds to foreign substances is - Correct answer: 5. It allows specific recognition of an antigen The part labeled as 5 here is the paratope region of the antibody. It is highly specific and binds to the antigen's epitope region. This specific binding mediated elimination of the antigen only and not other molecules that are native to the body. Incorrect answer: 1 The region marked as 1 is the B cells. Antibodies are produced by the B cells of the immune system. They produce antibodies but play no role in their binding to the antigen. 3 The region marked under 3 is the constant region of the heavy chain of the antibody molecule. They are also not responsible for specific binding. 5 The region marked as 5 is the constant region of the light chain. This region is found just below the paratope region but this does not help provide specificity in the binding.