Fiona wants to use the scientific method to answer the question “Do oxygen levels in the air affect rates of photosynthesis?” She reads about photosynthesis in her biology book and is ready to carry out the next step. What should she do next? perform an experiment
design a procedure
make observations
form a hypothesis

The first thing Fiona, or anyone, should do is form her hypothesis.

The hypothesis is your own proposed explanation for whatever phenomenon you're trying to study. Think of it as a predetermined idea of what could happen based on what you already know.

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.

answer; /// i believe that the correct answer is ( monophasic ); ethinyl estradiol- ethynodiol diacetate is a monophasic oral contraceptive agent; ///