Which one of the following is a living fossil?

Which of the following animals is $NOT$ included in the phylum $Platyhelminthes$?

Which of the following animals is hermaphrodite (bisexual)?

Some characteristics are given below:
$(1)$ Polymorphism $(2)$ Metagenesis $(3)$ Metamorphosis
$(4)$ Canal system $(5)$ Cnidoblast cells $(6)$ Blind sac body plan
Select the correct statement:

Assertion: All birds,except the ones like koel (cuckoo),build nests for retiring and taking rest during night time (day time for nocturnal).
Reason: Koel lays its eggs in the nests of tailor bird.

Comb jellies are ..................... and jelly fishes are .................. respectively.