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.

the correct answer is - ability to find a mate

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .