So I had some interesting questions!

I was studying and look up hard biology questions, or perhaps interesting. So I sorted them out and I wanted to ask the following questions.

Are gender traits completely a result of societal expectations?
Are there any parts of the human body that get oxygen directly from the air and not from the blood?
Are there nuclear reactions going on in our bodies?
Can humans ever directly see a photon?

What is the role of the mitochondria in the cell?

What is the difference between a prokaryotic and eukaryotic cell?
What is the role of enzymes in metabolism?
What is the difference between DNA and RNA?
What is the role of the Golgi apparatus in the cell?
What is the role of the endoplasmic reticulum in the cell?
What is the role of the ribosome in the cell?