Auxanometer is required for

Options

A. Studying rate of transpiration
B. Measuring rate of respiration
C. Finding out rate of photosynthesis
D. Calculating rate of growth

Answer

**Step-by-Step Solution:**

1. **Understanding Auxanometer**: An auxanometer is an instrument used to measure the growth of plants. It specifically measures the increase in length or height of plant parts over time.

2. **Analyzing the Options**:
- **Option 1: Studying rate of transpiration**: This is incorrect. The rate of transpiration is measured using a photometer, not an auxanometer.
- **Option 2: Measuring rate of respiration**: This is also incorrect. The rate of respiration is measured using a respirometer, which assesses the amount of CO2 produced and O2 consumed.
- **Option 3: Finding out rate of photosynthesis**: This option is incorrect as well. The rate of photosynthesis is measured using an infrared spectrometer, which calculates the amount of CO2 involved in the photosynthetic process.
- **Option 4: Calculating rate of growth**: This is the correct option. An auxanometer is specifically designed to measure the rate of growth in plants.

3. **Conclusion**: Based on the analysis of the options, the auxanometer is required for calculating the rate of growth.

**Final Answer**: The auxanometer is required for calculating the rate of growth.

---