1. (used with a sing. verb) A theory that explains the global distribution of geological phenomena such as seismicity, volcanism, continental drift, and mountain building in terms of the formation, destruction, movement, and interaction of the earth's lithospheric plates. 2. (used with a sing. or pl. verb) The dynamics of plate movement.
Despite the fact that mollusks are very susceptible to changes in their environment because of their permeable skin and soft body (often with an exoskeleton in the form of a shell), they have adapted to all of the main environments of our planetâmarine, freshwater, and terrestrial. With 41% of the 736 documented extinctions of all animal species, the number of mollusks exceeds that of any other major taxonomic group 3. 2  Most documented endangered mollusk species are non marine (they live in freshwater or terrestrial environments) 5.
Mollusca Worksheet 1. For what purpose do mollusks use their muscular foot? 2. How is the muscular foot of a squid different from that of clams and snails? 3. What is a mantle and where is it located in most mollusks? 4. What is contained in the visceral mass? 5. How do most sessile and burrowing mollusks obtain food? 6. What kind of digestive tract do mollusks have? 7. How do the nervous systems of clams and octopuses differ? 8. How do mollusks reproduce; sexually, asexually, or both? 9. Where does fertilization take place in mollusks?