Culture always plays a role in shaping what we understand as natural. what does this mean?

The term "culture" is equiavlent to the term " natural." Its what we "naturally" think, thus becoming a custom that is bid by, rather than shaped from the many diverse opinions. 
This is just an opinion. Its how I see it. But I think you should take this level a big higher. Ive just shared with you some basics. 

If you have any doubts, which im sure you may, please dont hesitate to say so. :) I hoped I helped you a little. 

This metaphor uses symbolism when describing the “arch” of ulysses life. he is trapped in a time of life where adventure is moving as he tries to proceed to it. he will never reach it and will learn to accept it. ulysses symbolizes that arch in life, that no one can reach every goal, or every sight in life. even though this personality of curiosity and purposefulness exist in all mankind, the purpose of showing his strive to succeed symbolizes great leaders today. his curiosity represents the curiosity of humans that everyone desires to find answers and wont give up without a fight. ulysses is a symbol of the human race.

Answerinterviewing there is no image showing, but i believe this is correct/// plz check first.good luck