Question

Give four general characters of phylum Mollusca. Write down two examples.

Answer 1

(i) Body is soft, bilaterally symmetrical, with little segmentation and without appendages. The size of body varies from a microscopic to a giant form such as Octopus of upto 50 feet.
(ii) Body cavity is haemocoel. True coelom is reduced and restricted to the pericardial cavity and the lumen of gonads and nephridia.
(iii) Digestive tract has a simple structure.
(iv) Sexes are usually separate.
Example: Octopus and Sepia.