What happens when high frequency shines on some metals? What is this called?

When a light with a sufficiently high frequency shines on a metal plate, electrons are ejected from the plate. This effect is known as the photoelectric effect. The electrons ejected in this process are called photoelectrons.

Explanation:

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.