Why is photosystem ii before photosystem i

Photosystems I and II are named such because Photosystem I was actually discovered (and named) before Photosystem II, even though Photosystem II comes before Photosystem I during photosynthesis (i.e., Photosystem II precedes Photosystem I in the electron flow of photophosphorylation).

humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of invasive species (such as new predators and food competitors), overhunting, and other influences. explosive, unsustainable human population growth is an essential cause of the extinction crisis.

explanation:

i didn't have the answer choices , but i tried my best.

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