The kidneys and bladder are important to your body's proper functioning. Which of these
describes the function of these organs?
A) Regulates fluid balance and eliminates waste.
B) Aids in reproduction.
C) Breaks down solid food.
D) Stores nutrients and vitamins.

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.