What do you mean by serological relationship?

Explanation

**Step-by-Step Solution:**

1. **Definition of Serological Relationship**:
- A serological relationship refers to the connection established between different animal groups based on the antigen-antibody reactions that occur in their blood.

2. **Understanding Antigens and Antibodies**:
- In the context of serology, antigens are substances that provoke an immune response, while antibodies are proteins produced by the immune system to neutralize or eliminate antigens.

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