20. Which of the following statements is/are correct?
A. Molluscs can live in marine, and freshwater habitats but do not live in terrestrial habitats.
B. Given the following on the organism:
I. An animal
II. Multicellular
III. has tissues
IV. has a digestive tract
V. exhibits bilaterally symmetry as an adult
This organism could be a member of the Phylum Mollusca
C. Molluscs can produce a shell and the presence of a shell at one point in development is a requirement for inclusion into this phylum.
D. Lobsters are members of the phylum Mollusca
E. Molluscs have three main body parts, a muscular foot, a visceral mass, and a head

Option C and E are correct.

Explanation:

Phylum molluscs are invertebrates species. They are the second largest phylum in the animal kingdom .Most mollusc live in marine and others live in freshwater and terrestrial habitat. Molluscs are ceoomates and they have three universal structures which are the mantle (breathing and excretion),radula and nervous system. The molluscs include snail, oyster,clams, periwinkles,octopus, squid e.t.c.

The larvae of molluscs are bilateral symmetrical while the adults are asymmetrical. Molluscs can produce shell, the presence of shell is an inclusion in the phylum.

Molluscs have three body part, the head, visceral mass and muscular foot

Options B and E are correct

Explanation: molluscs are found in freshwater, marine and terrestrial habitat. Some small species such as the land snail lives in dampy and dark places in terrestrial habitats. Molluscs are animal, are multicellular, have tissue, a digestive tract which includes mouth, stomach, anus and they also possess an oral structure called the radula. Some cephalopods do not have shells as they have lost their shells at one point in evolution and examples include octopuses. Lobsters are crustaceans belonging to the phylum arthropoda. Molluscs do have three main body parts head, visceral mass and the muscular foot.