Which among the following have an open circulatory system?
$(i)$ Arthropoda
$(ii)$ Mollusca
$(iii)$ Annelida
$(iv)$ Coelenterata

The locomotory organs of $Echinodermata$ are:

Fill in the boxes given in the figure with appropriate characteristics or plant groups.

$A$ plant specimen was found without differentiated roots.
$(a)$ Which plant structure helps in attaching this plant to the substratum?
$(b)$ To which group would you classify this plant?
$(c)$ Which plant could it be?

Why are bats not placed in birds?

Give examples for the following:
$(a)$ Bilateral,dorsiventral symmetry is found in ...............
$(b)$ Worms causing disease elephantiasis is ..............
$(c)$ Open circulatory system is found in ............. where coelomic cavity is filled with blood.
$(d)$ ............... are known to have pseudocoelom.