A plant in your garden avoids photorespiratory losses, has improved water use efficiency shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the followubg physiological groups would you assign this plant

Options

A. `C_(4)`
B. `CAM`
C. Nitrogen fixer
D. `C_(3)`

Answer

To determine the physiological group to which the described plant belongs, we can analyze the characteristics provided in the question step by step.

### Step 1: Identify the Characteristics
The plant in question has the following characteristics:
1. Avoids photorespiratory losses.
2. Improved water use efficiency.
3. High rates of photosynthesis at high temperatures.
4. Improved efficiency of nitrogen utilization.

### Step 2: Understand Photorespiration
Photorespiration is a process that occurs when the enzyme RuBisCO fixes oxygen instead of carbon dioxide, leading to a loss of carbon and energy. Plants that avoid photorespiration are typically those that have adapted mechanisms to minimize this process.

### Step 3: Water Use Efficiency
Plants that exhibit improved water use efficiency are often adapted to arid or semi-arid environments. They have mechanisms to reduce water loss, such as specialized leaf structures or photosynthetic pathways.

### Step 4: High Photosynthesis Rates at High Temperatures
Plants that can perform photosynthesis efficiently at high temperatures are usually those that have adapted to hot climates. This is often seen in C4 plants, which have a unique photosynthetic pathway that allows them to thrive in such conditions.

### Step 5: Nitrogen Utilization
Improved efficiency of nitrogen utilization suggests that the plant can utilize nitrogen more effectively, which is often a characteristic of certain plant types, including legumes and some C4 plants.

### Step 6: Compare with Physiological Groups
Now, let's compare these characteristics with the physiological groups provided:
- **C3 Plants**: Generally do not avoid photorespiration effectively and are less efficient in hot conditions.
- **C4 Plants**: Specifically adapted to avoid photorespiration, have high water use efficiency, thrive in high temperatures, and can utilize nitrogen effectively.
- **Nitrogen Fixers**: While they improve nitrogen utilization, they do not necessarily have the other characteristics mentioned.
- **CAM Plants**: Adapted for arid conditions but not specifically known for high temperatures or high nitrogen efficiency.

### Conclusion
Based on the analysis, the plant described in the question fits the characteristics of **C4 plants**. They are known for avoiding photorespiratory losses, having improved water use efficiency, high rates of photosynthesis at high temperatures, and improved nitrogen utilization.

### Final Answer
The plant belongs to the **C4 physiological group**.

---