In the Z-scheme of `e^(-)` transport , PSII and PSI are connected by

Options

A. NADPH
B. ATP
C. photos
D. Electron transport chain

Answer

**Step-by-Step Solution:**

1. **Understanding the Z-scheme**: The Z-scheme is a model that describes the light-dependent reactions of photosynthesis, specifically how electrons are transferred through two photosystems: Photosystem II (PSII) and Photosystem I (PSI).

2. **Role of Photosystems**: In the Z-scheme, PSII absorbs light energy, which excites electrons. These high-energy electrons are then transferred to PSI.

3. **Connection Between PSII and PSI**: The electrons that are excited in PSII are not directly transferred to PSI. Instead, they pass through a series of proteins and molecules known as the electron transport chain.

4. **Electron Mediators**: The electron transport chain consists of various electron mediators that facilitate the transfer of electrons from PSII to PSI. These mediators include plastoquinone, cytochrome b6f complex, and plastocyanin.

5. **Final Answer**: Therefore, in the Z-scheme of electron transport, PSII and PSI are connected by the electron transport chain.

**Final Answer**: The correct answer is the electron transport chain.

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