The basis of classification of phylum Mollusca is

• A. Morphology
• B. Respiratory organs
• C. Both a and b
• D. Shell

The classification of phylum Mollusca is primarily based on several factors, including their morphology and respiratory organs. Therefore, the correct answer is:

Answer

C. Both a and b

Explanation

Mollusca is a diverse group of animals that includes snails, clams, and octopuses. Their classification relies on:

• Morphology: This refers to the physical structure and form of the organisms, such as body shape and shell characteristics.
• Respiratory organs: Different mollusks have various types of respiratory systems, which also play a role in their classification.

Both of these aspects are crucial for understanding the relationships and differences among the various classes within the phylum Mollusca.