Kingdom Animalia

Carapace is the dorsal part of the shell of turtle or tortoise which belongs to order-Chelonia of class-Rcptilia. These organisms are easily identified by their armoured shell by bony plates consisting of dorsa! carapace and a ventral plastron when this animal is threatened with danger, the head neck, limbs and tail are with-drawn into the shell,

In mollusca, each eye is located upon a stumpy peduncle called ommatophore. In mollusca, a loose skin fold, called mantle, dorsally covers most of the body and encloses a large mantle cavity. The mantle cavity contains the rectum, genital duct, a penis in males and a small bipectinate chemoreceptor called osphradium. In mollusca, the large oval aperture or mouth of the shell can be tightly closed by a thick, plate-like operculum attached to the foot.

Pseudocoelom: Body cavity is false coelom, derived from embryonic blastocoel. e.g.; Aschelminthes (Ascaris). In pseudocoelomates, there is a liquid filled space in which body organs float. Eucoelom or true coelom is lined with two layers of mesodenn e.g., earthworms. It nu) be schizocoelom or emerocoelom. Schizocoelom is the true coelom, originate by splitting of mesoderm and its enlargement to form the cavity e.g; Annelida. Arthropoda, Mollusca). Haemocoelom is the true coelom, filled with blood. It is found in arthropods, some annelids and molluscs, where the circulatory system open type (with blood sinuses and lacunae).

Answer (c) Chemoreceptor

Answer (b) Excretion

Answer (b) Contamination