Identify the location and function of the following structures:
$(i)$ Water vascular system
$(ii)$ Cloaca

Peripatus is a connecting link between

Match the following genera with their respective phylum:

$(a)$ Ophiura	$(i)$ Mollusca
$(b)$ Physalia	$(ii)$ Platyhelminthes
$(c)$ Pinctada	$(iii)$ Echinodermata
$(d)$ Planaria	$(iv)$ Coelenterata

Select the correct option:

Read the following statements.
$(a)$ Metagenesis is observed in Helminths.
$(b)$ Echinoderms are triploblastic and coelomate animals.
$(c)$ Round worms have organ-system level of body organization.
$(d)$ Comb plates present in ctenophores help in digestion.
$(e)$ Water vascular system is characteristic of Echinoderms.
Choose the correct answer from the options given below.

Which of the following phyla possess an open circulatory system?

Choose the correct difference between $Pristis$ and $Catla$.