Final answer:
The incorrect statement about photosystems is 'Photosystem I passes electrons on to Photosystem II.' The correct order is Photosystem II passing electrons to Photosystem I, which are critical components in the light-dependent reactions of photosynthesis. The correct option is a.
Step-by-step explanation:
The statement that is NOT true about photosystems is A. Photosystem I passes electrons on to Photosystem II. This is incorrect because the flow of electrons is from Photosystem II to Photosystem I. Photosystems are a crucial part of the light-dependent reactions of photosynthesis and are located in the thylakoid membranes of chloroplasts. They are both responsible for converting light energy into chemical energy in the form of NADPH and ATP, which are later used in the Calvin cycle to produce glucose.
The correct sequence of electron flow in the light-dependent reactions begins with Photosystem II, where the energy from sunlight is used to extract electrons from water (H2O), releasing oxygen as a byproduct. These excited electrons then pass through an electron transport chain to Photosystem I. Photosystem I receives these electrons and uses further light energy to boost them to a higher energy level. They are then used to produce NADPH. The process of moving these electrons through the chain and creating a proton gradient also facilitates the production of ATP via ATP synthase.
Photosystem II and I also have light-harvesting complexes or antennae complexes that contain pigments like chlorophyll a, chlorophyll b, and carotenoids. These pigments capture the energy from sunlight and pass it to the reaction center, causing the excitation of electrons. All these components work synergistically to convert solar energy into a usable chemical form.