Which statements are true about all the natural chemical cycles?

-each cycle can operate and balance itself

-each cycle affects other cycles

-natural earth cycles cannot be disturbed

-human activity has upset cycles in local areas

-all the natural cycles work together to support life

Each cycle affects other cycles. All the natural cycles work together to support life. Human activity has upset cycles in local areas.

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.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !