Which of the following animals is hermaphrodite (bisexual)?

Distinguish the characteristics for Chondrichthyes (Cartilaginous fishes) and Osteichthyes (Bony fishes) from the following list:
$I$ - Air bladder absent,$II$ - Operculum absent,$III$ - Cycloid or ctenoid scales,$IV$ - Placoid scales,$V$ - Ventral mouth,$VI$ - Terminal mouth,$VII$ - Internal fertilization,$VIII$ - External fertilization.
Select the correct grouping for Chondrichthyes and Osteichthyes respectively.

What are the characteristics of Platyhelminthes and Aschelminthes?

Which one of the following statements regarding the given animals is correct?

Select the animals having an open type of circulatory system:
$(i)$ $Ascidia$
$(ii)$ $Cockroach$
$(iii)$ $Earthworm$
$(iv)$ $Prawn$
$(v)$ $Silver$ $fish$
$(vi)$ $Snail$
$(vii)$ $Squid$

Choose the correct option for the following statements:
$(i)$ Birds are oviparous / viviparous animals showing internal fertilization.
$(ii)$ In cartilaginous fishes,gill slits are without operculum / with operculum.