The existence of the plasma membrane was identified in the 1890s, and its chemical components were identified in 1915. the principal components identified at that time were these?

The four Science Regents exams (Earth Science, Living Environment, Chemistry, and Physics) also include separately-scheduled lab practicals.
In New York, students have the opportunity to take Regents Exams in grades 9-12 and, when appropriate, in grade eight.