Question 1
which of the following can best explain why eukaryotic cells must use mechanisms other than diffusion to
transport materials around the cell?
in eukaryotic cells, materials can flow through microtubules
enzymes cannot attach to eukaryotic membran
random movement of molecules is not fast enough to disperse through the larger eukaryotic cell volume,
in eukaryotic cells, internal membranes get in the way and block diffusion

Random movement of molecules is not fast enough to disperse through the larger eukaryotic cell volume,

Explanation:

Eukaryotic clels are much bigger than prokaryotic cells. The latter may be 0.5 um while the former may be 100 um (which is more than 10X in comparative size). Prokaryotic cells, therefore, have a larger surface area to volume ration that suits them to use diffusion to eliminate waste and take up nutrients. However eukaryotic cells cannot adopt this mechanism due to their smaller surface area-to-volume ratio which would cause them to accumulate waste to toxicity levels. Eukaryotic cells, therefore, use additional vesicle transport to take up nutrient and eliminate waste in bulk.

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.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.