A. histamine released from mast cells causes relaxation of smooth muscle in the walls of capillaries, which increases local blood flow. b. during inflammation, plasma proteins leak into the extravascular space, increasing the rate at which water leaves capillaries by osmosis. c. delivery of oxygen and nutrients is aided by increased fluid flow through inflamed areas. d. neutrophils accumulate in the extravascular space in inflamed areas. e. both basophils and mast cells are granulocytes.

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.

this is a good question! i'll do some research and come back when i have the answer!