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3.3 Mollusca — Test 1
Q1. The function of the osphradium in Pila is:✓ To test the quality (purity) of incoming water
Q2. Oysters, clams and mussels all belong to the molluscan class:✓ Bivalvia
Q3. The rasping feeding organ found in most molluscs (but not bivalves) is the:✓ Radula
Q4. In Unio (a freshwater bivalve), the respiratory organs are the:✓ Ctenidia (gills)
Q5. The innermost, lustrous layer of a mollusc shell, which forms pearl, is the:✓ Nacre (mother-of-pearl)
Q6. Torsion in gastropods is the result of twisting of the:✓ Visceral mass
Q7. The octopus, squid and cuttlefish belong to the molluscan class:✓ Cephalopoda
Q8. Cephalopods move rapidly by:✓ Jet propulsion (forcing water from the mantle cavity)
Q9. The largest living bivalve, providing a giant shell, is:✓ Tridacna gigas
Q10. The body of a mollusc is typically covered by a fold of tissue that secretes the shell, called the:✓ Mantle
3.3 Mollusca — Test 2
Q11. The chambered nautilus differs from the octopus in having:✓ An external coiled shell
Q12. Statocysts, organs of balance, are found in molluscs such as:✓ Cephalopods and many gastropods
Q13. The radula of a mollusc is used mainly for:✓ Feeding (rasping or scraping food)
Q14. Pearls are formed when the mantle secretes nacre around:✓ An irritant such as a sand grain or parasite
Q15. The devil fish, a member of phylum Mollusca, is the:✓ Octopus
Q16. Molluscs typically have a soft body divisible into a head, a muscular foot and a:✓ Visceral mass covered by a mantle
Q17. Cephalopods have a highly developed nervous system and eyes that are an example of ____ with vertebrate eyes:✓ Convergent evolution
Q18. The foot of a gastropod (snail) is chiefly used for:✓ Creeping locomotion
Q19. Bivalves feed by:✓ Filtering food particles from water using their gills
Q20. The shell of a mollusc is secreted by the mantle and is made mainly of:✓ Calcium carbonate