A campfire is a good source of heat and light on a cool night. The energy that is released when firewood is burned comes from
A.
the kinetic energy of the moving flames.
B.
the energy used to carry the wood.
C.
the chemical bonds in the wood.
D.
the energy used to strike the match.

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.