In higher plants the by product of photo-synthesis is

Options

A. `O_2`
B. `H_2O`
C. Carbohydrates
D. ATP

Answer

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis is a process used by higher plants to convert light energy into chemical energy, primarily in the form of glucose (a carbohydrate). It occurs in the chloroplasts of plant cells.

2. **Photosynthesis Equation**: The general equation for photosynthesis can be represented as:
\[ 6 \text{CO}_2 + 6 \text{H}_2\text{O} \xrightarrow{\text{light, chlorophyll}} \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 \]
This indicates that carbon dioxide (CO2) and water (H2O) are used to produce glucose (C6H12O6) and oxygen (O2).

3. **Identifying Products and By-products**: In the process of photosynthesis:
- The main product is glucose (or carbohydrates).
- Oxygen is released as a by-product.

4. **Analyzing the Options**:
- **Option A: Oxygen (O2)** - This is the by-product of photosynthesis.
- **Option B: Water (H2O)** - This is a reactant, not a by-product.
- **Option C: Carbohydrates (e.g., starch)** - This is the main product of photosynthesis, not a by-product.
- **Option D: ATP** - This is an energy currency produced during the light reactions but is not a by-product.

5. **Conclusion**: Based on the analysis, the by-product of photosynthesis in higher plants is **oxygen (O2)**.

### Final Answer:
The by-product of photosynthesis in higher plants is **oxygen (O2)**.

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