What is present between the two germ layers in the phylum $Cnidaria$?

Which of the following is $NOT$ a function of the cnidoblast (nematocyst)?

In the phylum $Coelenterata$ $(Cnidaria)$,what are the sequential names of the asexual and sexual stages?

Identify the correct features for $Medusa$ and $Polyp$ forms in Phylum $Coelenterata$ (Cnidaria) from the given list:
$I$ - $Sessile$
$II$ - $Umbrella-shaped$
$III$ - $Free-swimming$
$IV$ - $Produced$ $by$ $asexual$ $reproduction$
$V$ - $Cylindrical$
$VI$ - $Produced$ $by$ $sexual$ $reproduction$
$Medusa$ $\quad\quad$ $Polyp$

Hydra receives impulses and stimuli through

"Polymorphism" is observed in members of the class: