The largest part of the human brain is the (paired) the other major subdivisions of the brain are the and the the cavities found in the brain are called they contain

The largest part of the human brain is the (paired) CEREBRAL HEMISPHERS___(1),

the other major subdivisions of the brain are the _BRAIN_(2)___ and the _STEM_(3)__.

 the cavities found in the brain are called VENTRICLES__(4)__.

they contain _CEREBOSPINAL FLUID_(5)_(CSF.)_.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.