Certain chemical substances having profound effect on growth ,are called
(a) Catalytic agents
(b) Phytohormones
(c) Enzymes
(d) Compost

Options

A. Catalytic agents
B. Phytohormones
C. Enzymes
D. Compost

Answer

To solve the question regarding which chemical substances have a profound effect on growth, we will analyze each option provided:

1. **Understanding the Options**:
- **(a) Catalytic agents**: These are substances that speed up chemical reactions but do not necessarily have a direct effect on growth.
- **(b) Phytohormones**: These are chemical messengers in plants that regulate growth and development. They have a profound effect on various physiological processes in plants.
- **(c) Enzymes**: While enzymes are crucial for biochemical reactions, they are not specifically known for their role in growth regulation.
- **(d) Compost**: This is organic matter that improves soil fertility but is not a chemical substance that directly influences plant growth.

2. **Identifying the Correct Answer**:
- Among the options, **phytohormones** (option B) are specifically known for their significant impact on plant growth and development. They coordinate various cellular activities and play vital roles in processes such as cell division, elongation, and differentiation.

3. **Conclusion**:
- Based on the analysis, the correct answer to the question is **(b) Phytohormones**.