In your work with antibiotics in the lab, you need to find out the lowest concentration of an antibiotic that would be needed to inhibit the growth of organism X under laboratory conditions. The item you would use beside the agar plate to determine the minimum inhibitory concentration (MIC) is an .

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.

i think its c. amphipod