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

All organisms that are similar enough to breed and perpetuate are called

Give reasons for the following:
$(a)$ Echidna and Platypus lay eggs but are considered as mammals.
$(b)$ Birds have pneumatic bones.

Which one is a true fish?

State whether the following statement is true or false:
The plants of the $Angiosperm$ group bear naked seeds.

Study the figure and answer the following questions:
$(a)$ Label $A$ and $B$.
$(b)$ Identify the organism and its kingdom.
$(c)$ Name two organisms (other than the one shown here) belonging to the same kingdom.