Cnidarians exhibit two basic body forms called medusa (sessile and cylindrical form) and polyp (free-swimming and umbrella shaped). A, C, D, G, H, N, P

The phenomenon exhibited by some Cinidarians in which both forms exhibit alternation of generation is termed as metastasis. F, H, I, J, L, P, Q

Polyps produce medusae by sexually and meduase forms polyp by asexually reproduction. A, B, C, I, K, O, P

Physalia is known as Portuguese man-of-war; Adamsia as Sea anemone; Pennatula as Sea pen; Gorgonia as Sea fan andMeandrina as Brain coral. (E) Ctenophores are commonly known as seawalnuts or comb jellies. (F) Ctenophores are exclusively marine and body bears eight external rows of ciliated comb plates that help in locomotion. (G) Bioluminescence is the property of living organism to emit light and is well marked by ctenophores. (H) Reproduction in ctenophore takes place by sexual means. Fertilisation is external with indirect development. (I) Hooks and Sucker are present in parasitic form of members of Aschelminthes. (J) Hooks and Sucker are present in pararsitic form of members of Aschelminthes. (K) In Platyhelminthes, fertilization is internal with direct development. (L) Some members of platyhelminthes like planaria possess high regeneration capacity. (M) Taenia, a member of phylum Platyhelminthes is commonly called tapeworm and fasciola is commonly called as liver fluke. (N) The alimentary canal in members of aschelminthes is complete with a well-developed muscular pharynx. (O) The males are longer than females in members of aschelminthes. (P) The members of aschelminthes are dioecious as sexes are separate. Fertilisation is internal and development is indirect. (Q) Ascaris, a member of phylum aschelminthes are commonly known as round worms; Wuchereria as filarial worm and Ancyclostoma as hookworms. D, E, J, K, L, O, P