Question

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

Answer 1

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.