Electrons from excited chlorophyll molecule of photosystem II are accepted first by

Options

A. Cytochrome - b
B. Cytochrome - f
C. Plastoquinone
D. Ferredoxin

Answer

To solve the question regarding which molecule first accepts electrons from the excited chlorophyll in photosystem II, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Photosystem II**: Photosystem II (PSII) is a complex of proteins and pigments (like chlorophyll) that plays a crucial role in photosynthesis. It captures light energy and initiates the process of converting that energy into chemical energy.

**Hint**: Photosystem II is involved in the light-dependent reactions of photosynthesis.

2. **Excitation of Chlorophyll**: When chlorophyll absorbs light, it becomes excited and releases electrons. This is a key step in the light-dependent reactions.

**Hint**: Remember that chlorophyll is the pigment responsible for capturing light energy.

3. **Electron Transfer**: The excited electrons from chlorophyll need to be transferred to another molecule. In PSII, the first molecule to accept these electrons is crucial for the continuation of the photosynthetic process.

**Hint**: Think about the sequence of electron transport in photosynthesis.

4. **Identify the First Electron Acceptor**: The first molecule to accept the electrons from the excited chlorophyll in PSII is plastoquinone. Plastoquinone is a type of quinone that plays a significant role in the electron transport chain.

**Hint**: Plastoquinone is specifically involved in the transfer of electrons from photosystem II to the next components in the electron transport chain.

5. **Eliminate Incorrect Options**: The other options provided (Cytochrome b, Cytochrome f, and Ferredoxin) are involved in later stages of the electron transport chain but do not accept electrons directly from the excited chlorophyll in PSII.

**Hint**: Knowing the roles of these proteins can help you understand why they are not the correct answer.

### Final Answer:
The electrons from the excited chlorophyll molecule of photosystem II are accepted first by **Plastoquinone**.