Question

explain phylum mollusca deeply​

Answer 1

Answer:

mollusca

Explanation:

* Free living , mostly marine

*TWT , billatery symmetrical but few asymmetrical .

*Mantle secrets a hard calcareous shell

• *locomotory organ arm & foot
• Complete digestive system
• Rasping organ radula
• numerous gills called ctenidia
• lungs
• open type circulatary sys
• haemocyanine respiratory pigment
• excretion by kidney also known as bojanus
• Three pairs of ganglion in nervous system
• eyes, tentacles etc
• oviparous , direct or indirect development
• ex. chiton , dentalium , pila, bivalve , sepia , octopuss