After light excites electrons and they leave the photo system II to travel down the first electron transport chain. How are these electrons replaced to photo system II?

Question

A. Oxygen is reduced and the electrons are given to the chlorophyll molecules of photo system II.
B. Water is split and the electrons are given to the chlorophyll molecules of the photo system II
C. Carbon dioxide is split and the electrons are given to the chlorophyll molecules of photosystem II.
D. hydrogen undergoes fusion and the electrons are given to the chlorophyll molecules of photosystem II.

Answer 1

The correct answer is B. Water is split and the electrons are given to the chlorophyll molecules of photosystem II.

In photosynthesis, specifically in the light-dependent reactions, when electrons are excited by light energy in photosystem II (PSII) and move down the electron transport chain, the electrons that leave PSII are replaced by electrons obtained from the splitting of water molecules (a process known as photolysis). This reaction also releases oxygen as a byproduct.