Suppose that during any period of ¼ second there is one instant at which the crests or troughs of component waves are exactly in phase and maximum reinforcement occurs. how many beats will occur in 1 second?           a. 8   b. 12   c. 2   d. 4

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.

a. seed plant structure. 1. the three main plant organs are roots, stems, and leaves. a fourth kind of tissue, meristematic tissue, is responsible for plant growth. meristematic tissue is the only plant tissue that produces new cells by mitosis. plants can lose water out of their leaves as they exchange gases with the air

explanation: