14. What type of exoskeleton
do some molluscs present?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
Some molluscs, like and
gastropods, secrete external
calcareous carapace ( shell). Calcium
carbonate secreted by the , a
fold in epidermis, forming the .
In pelecypods, the is made of
valves that articulate contain the
individual within. In gastropods
shell contains only of the body,
visceral mass.