Phylum Molluscs
Answers are for parents and teachers.
1
Compare the pond snail and mussel by 4 features.
Pond snail: coiled shell, has a head, lung, radula. Mussel: two valves, no head, gills, filter feeder.
2
Name the three classes of molluscs and an example of each.
Gastropods – pond snail; bivalves – mussel; cephalopods – squid.
3
Why is the mussel useful for a water body?
It filters the water and removes microorganisms and particles.
4
What harm do grape snails and slugs cause? How can it be fought?
They eat green parts of crops. Control: handpicking (with gloves), tidiness, and safe methods chosen by adults.
5
Explain the cephalopods’ complex structure in 3 sentences.
Strong brain, tentacles with suckers, jet propulsion, ink sac; no outer shell.