Water add about 4°c is more dense than water at 0°c why would the living organisms in the lake die if the water at the frozen point was denser than the water at 4°c

asfe afr dsef rfdg fghgnts fhbfgd   hdfdx

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.