Factors present on the surface of RBCs which are related to heredity are

Options

A. Blood group
B. Haemoglobin
C. Antigens
D. Antibodies.

Answer

To answer the question regarding the factors present on the surface of red blood cells (RBCs) that are related to heredity, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Components of RBCs**: Red blood cells (RBCs) have various components on their surface, including proteins and carbohydrates. These components can play roles in blood typing and immune responses.

2. **Understand the Role of Antigens**: Antigens are substances that can trigger an immune response. In the context of RBCs, certain proteins on their surface are classified as antigens. These antigens can determine blood groups.

3. **Explore Blood Groups**: Blood groups (such as A, B, AB, and O) are determined by the presence or absence of specific antigens on the surface of RBCs. The ABO blood group system and the Rh factor (Rhesus factor) are the most well-known blood group systems.

4. **Connect Antigens to Heredity**: Antigens on RBCs are inherited from parents. Each parent contributes alleles that determine the presence of specific antigens. For example, the Rh factor can be either positive (Rh+) or negative (Rh-), and this trait is inherited in a Mendelian fashion.

5. **Conclude with the Correct Answer**: Given that the question asks for factors related to heredity present on the surface of RBCs, the correct answer is "antigens." These antigens are genetically determined and inherited from the parents.

### Final Answer:
The factors present on the surface of RBCs that are related to heredity are **antigens**.

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