What are the biggest challenges to organisms in the tundra biome? migrating to warm areas and finding food
surviving cold temperatures and finding trees to live in
surviving the cold temperatures and obtaining and keeping enough water
finding enough food and obtaining and keeping enough water

Surviving cold temperatures and finding trees to live in

Explanation:

The major problems of tundra biome are oil, gas, mining industries

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.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.