Question

Pila has a
A) Gill
B) Pulmonary sac
C) Trachea
D) Both A and B

Answer 1

Hint:Pila is a genus that belongs to the class Gastropoda of phylum Mollusca. These are large freshwater snails with operculum. These are found in Africa, Madagascar, Southern Asia and Indo-Pacific Islands.

Complete answer:
>Molluscs are soft-bodied organisms with organ system organization and bilateral symmetry except snails that are asymmetrical due to their shells.
>They are triploblastic and true coelomates. They are mostly marine but some occur in damp soil and some occur in freshwater.
>They have an unsegmented body with three parts- ventral and muscular foot, head with sensory tentacles and visceral mass. The mantle secretes a calcareous shell of calcium carbonate. Shell is generally external but may be internal also.
>They have a complete digestive tract and the buccal cavity has a rasping and feeding organ called radula.
>They have an open type of circulatory system and the color of the blood is blue due to the presence of copper containing haemocyanin that gets dissolved in the blood.
>They also have a peculiar sense organ called osphradium that tests the chemical nature of the ingoing water.
>Excretion occurs by one or two pairs of kidneys called metanephridia.
>They are generally unisexual and the fertilization may be external or internal. Development may be direct or indirect.

Hence the correct answer is option ‘D’.

Note:Mollusca is the second largest phylum of animal kingdom, after Arthropoda and includes over 100,000 species. Some examples of Molluscs are Neopilina, Pila (Apple snail), Loligo (Squid), Dentalium, etc.