Shell of molluscs is derived from
foot
mantle
ctenidia
placoid
B.
mantle
Molluscs are soft bodied, unsegmented animals covered by a shell. Mantle is present between the shell and body wall, which secretes the shell.
Which of the following cell type is capable of giving rise to other cell types in sponges?
Thesocytes
Pinacocytes
Cnidocytes
Archaeocytes
Animals having a built in thermostat to maintain constant body temperature are known as
biothermic
poikilothermic
oligothermic
homeothermic