Question

Which of the following represents the correct order of events? (1 point)
the element oxygen was discovered, urea was synthesized, proteins were crystallized, the structure of DNA was discovered
the structure of DNA was discovered, proteins were crystallized, the element oxygen was discovered, urea was synthesized
the element oxygen was discovered, proteins were crystallized, the structure of DNA was discovered, urea was synthesized
urea was synthesized, proteins were crystallized, the element oxygen was discovered, the structure of DNA was discovered

Answer 1

This is the years if I remember right, then you can put them in the right order your self.
In 1828-1831 the inorganic NH4+, -OCN was made to the organic compound (NH2)2CO (urea)
The first good and acknowledge model of DNA was in 1950's (about 1953).
The found of oxygen was about 1772-1776
Protein crystalization is a bit hard because it have been used for long but we have become better at it. I would say around the 1910's to the 1930's