In light reactions of photosynthesis why photosystem 2 occurs before photosystem 1

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Where can dna be found in a prokaryotic cell

Facilitated diffusion move large molecules and/or polar molecules across the cell membrane. what does facilitated diffusion use to do this?