Moulting hormone is secreted by
corpora cardacum
corpora allata
neurosecretory hormone
prothoracic gland
Shell of molluscs is derived from
foot
mantle
ctenidia
placoid
B.
mantle
Molluscs are the soft bodied, unsegmented animals covered by a shell. Mantle is the dorsal body wall which covers the organs of digestion, reproduction and movement. In between the shell and body wall is a covering called mantle, which secretes the shell.