Sperm of animal speciea a cannot fertilise ovum of species b because

Options

A. Fertilizin of a and b are not compatible
B. Antifertizin of a and b are not compatible
C. Fertilizin of a and antifertilizin of b are not compatible
D. Antifertilizin of b are not compatible.

Answer

To answer the question "Sperm of animal species A cannot fertilize ovum of species B because," we need to understand the interaction between sperm and egg cells, specifically focusing on the concepts of fertilizants and antifertilizants.

### Step-by-Step Solution:

1. **Understanding Sperm and Egg Interaction**:
- Sperm and egg cells have specific proteins on their surfaces that facilitate fertilization. The sperm has substances known as fertilizants, while the egg has antifertilizants.

2. **Definition of Fertilizants and Antifertilizants**:
- **Fertilizants**: These are glycoproteins present on the surface of the sperm that help in the binding and fertilization process.
- **Antifertilizants**: These are substances found on the surface of the egg, composed of acidic amino acids, which can inhibit fertilization by preventing sperm from binding.

3. **Agglutination Process**:
- The interaction between fertilizants and antifertilizants can lead to a process called agglutination. This process ensures that only sperm from the same species can successfully bind to and fertilize the egg.

4. **Species-Specific Compatibility**:
- For fertilization to occur, the fertilizants of the sperm must interact appropriately with the antifertilizants of the egg. If they are not compatible, fertilization will not take place.

5. **Conclusion**:
- In this case, sperm from species A cannot fertilize the ovum of species B because the antifertilizants present on the egg of species B are not compatible with the fertilizants from species A. This incompatibility prevents the sperm from binding to the egg, leading to unsuccessful fertilization.

### Final Answer:
Sperm of animal species A cannot fertilize ovum of species B because the antifertilizants of species B are not compatible with the fertilizants of species A.

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