In light reaction, pigments are organised into two photochemical complexes called

Options

A. Photosystem - I and Photosystem - II
B. Light harvesting complexes
C. Antennae
D. None of the above

Answer

To solve the question, we need to identify the two photochemical complexes involved in the light reactions of photosynthesis. Here’s a step-by-step breakdown:

### Step 1: Understand the Light Reactions
The light reactions of photosynthesis occur in the thylakoid membranes of chloroplasts and involve the conversion of light energy into chemical energy.

### Step 2: Identify the Key Components
In the light reactions, pigments such as chlorophyll absorb light energy. These pigments are organized into complexes that facilitate the process of photosynthesis.

### Step 3: Recognize the Two Photochemical Complexes
The two main photochemical complexes involved in the light reactions are:
- **Photosystem I (PSI)**
- **Photosystem II (PSII)**

### Step 4: Mention the Role of Light Harvesting Complex
In addition to PSI and PSII, there is also a Light Harvesting Complex (LHC) that contains various pigments. The LHC captures light energy and transfers it to the reaction centers of PSI and PSII.

### Step 5: Conclusion
Thus, the two photochemical complexes in the light reactions are Photosystem I and Photosystem II.

### Final Answer
The correct answer is: **Photosystem I and Photosystem II**.

---