16. mendel suggested that the alleles for tallness and
shortness in the f1 plants segregated from each other
ring the formation of the sex cells.

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.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint