They're assembled in the endoplasmic reticulum. It's the organelle where lipid components of the cell membrane are assembled, as well as proteins and other materials are exported from the cell.
Answer: Rosalind Franklin
Explanation: Rosalind was the first oerson to get a picture while Watson and Crick came up with the strusture and won the nobel piece prize
To find out how they form
From reasoning and analyzing evidence. Hope this helped :D