Question

___________ is the second largest Phylum in the Animal Kingdom.

Answer 1

Hint: Second largest Phylum is both terrestrial and aquatic

Complete answer:
Mollusca is the second largest Phylum in the Animal Kingdom. Molluscs are both terrestrial and aquatic (marine or freshwater). They have an organ-system level of organisation. They are bilaterally symmetrical, triploblastic and coelomate animals. Their body is covered by a shell. They have a distinct head, muscular foot and visceral hump. Mantle cavity is the space between the visceral hump and soft skin, in which feather-like gills are present. They have distinct respiratory and digestive functions. Anterior head has sensory organs, Radula is the feeding organ. They are diacious, oviparous and undergo indirect development.

Additional Information:
Usually molluscs are hermaphrodites, that is they are diacious, produce both male and female gametes and do not need a partner for sexual reproduction. Molluscs are further divided into six classes; Monoplacophora, Amphineura, Scaphopoda, Gastropoda, Bivalvia and Cephalopoda; each of them have a distinct character. Molluscs have several economic importance - they are used as food, for decoration, in jewelry, and in scientific studies. They are even used as roadbed material and in vitamin supplements.

Notes:
- The largest phylum in the animal kingdom is Arthropods.
- Examples of Molluscs include - Pila, Pinctada, Loliga, Octopus, Dentalium etc.
- Chordata is the third largest phylum in Animal Kingdom.