Find the odd example.

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Amphibia	$(1)$ Air bladder
$(b)$ Mammalia	$(2)$ Cartilaginous notochord
$(c)$ Chondrichthyes	$(3)$ Mammary gland
$(d)$ Osteichthyes	$(4)$ Pneumatic bones
$(e)$ Cyclostomata	$(5)$ Dual habitat
$(f)$ Aves	$(6)$ Jawless,circular,sucking mouth

Which of the following statements are true or false?
$(i)$ Suckers are found in liver fluke.
$(ii)$ In Arthropods,fertilization is external.
$(iii)$ Chordata is divided into $4$ subphyla.
$(iv)$ Water vascular system is present in Hemichordata.

Flatworms and roundworms are respectively called ........

What is common among bed bugs,leeches,and mosquitoes?

Which of the following organisms exhibits body segmentation?