Use the drop down menus to complete the sentence describing the important ideas in Hess’s theory. Hess expanded on Wegener’s theory of BLANK. Hess proposed the idea that BLANK are places where crust is created

wegener’s theory of continental drift; hess proposed the idea that mid ocean ridges are where crust is created

Explanation:

wegener’s theory of continental drift; hess proposed the idea that mid ocean ridges are where crust is created

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.