CLASS CEPHALOPODA (L. cephalic, head + Or. podos, foot) The class Cephalopoda includes the octopuses. squid, cuttlefish. and nautili. They are the most complex molluscs. The anterior portion of their…
CLASS BIVALVIA (bis, twic + vala; leaf) There are 30,000 species of this class. It is the second largest molluscan class. This class includes the clams, oysters, mussels, and scallops.…
CLASS GASTROPODA (Or. gaster, gut + podos, foot) The class Gastropoda includes the snails. limpets, and slugs. It has 35.000 living species. It is the largest class of molluscs. Its…
CLASSIFICATION 1. Class Caudofoveata 1.They are wormlike molluscs. 2. They have cylindrical, shell-less body and scale like, calcareous spicules. 3. They lack eyes, tentacles, statocysts. crystalline style, foot, and nephridia.…
MOLLUSCAN CHARACTERISTICS The size of molluscs varies greatly. The largest body form is the giant squid 18 m in length. The smallest garden slug is less than 1 cm long.…
MOLLUSCAN SUCCESS EVOLUTIONARY PERSPECTIVE Some of the molluscs like octopuses, squids, and cuttlefish (the cephalopods) are most adapted predators. The evolution of large brains in them takes place due to…
OBJECTIVES Multiple Choice Questions MCQs 1. Which is irrelevant for aschelminths? (a) Cutely (b) Mesenteries (c) Protonephridia (d) Cephalization 2. The constant number of cell in an organ or tissue…
SUBJECTIVE QUESTIONS Discuss evolutionary perspective of the Aschelminthes. Give general characteristics of Aschelminthes. Give general characteristics of Rotifera. Describe external features of Rotifers. Discuss feeding and digestive system in Rotifers.…
DEFINITIONS & KEY POINTS FOR OBJECTIVES TERMS DEFINITIONS Cutely In this case, numbers of cells are constant in the entire animal and in each given organ in all…
FURTHER PHYLOGENETIC CONSIDERATIONS The aschelminths are diverse animals. They have common cuticle, pseudocoelom, muscular pharynx and adhesive glands. But no distinctive features in every phylum. 1. Origin of Rotifers The…
saadia