Plants produce an enormous diversity of substances that have no apparent roles in growth and development processes are classified under the heading of -

Options

A. Primary metabolites
B. Secondary metabolites
C. Necessary metabolites
D. Tertiary metabolites

Answer

To solve the question about the classification of substances produced by plants that have no apparent roles in growth and development, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Metabolites**:
- Plants produce various substances that can be categorized based on their roles in metabolic processes. The two main categories are primary metabolites and secondary metabolites.

2. **Define Primary Metabolites**:
- Primary metabolites are essential for the growth and development of plants. They include substances like carbohydrates, proteins, lipids, and nucleic acids that are directly involved in the plant's metabolism and growth processes.

3. **Define Secondary Metabolites**:
- Secondary metabolites, on the other hand, are compounds that are not directly involved in the growth, development, or reproduction of the plant. They often play roles in defense mechanisms, signaling, and interactions with the environment.

4. **Identify the Classification**:
- The substances that have no apparent roles in growth and development are classified as **secondary metabolites**. These can include alkaloids, flavonoids, terpenes, and phenolics, which serve various ecological functions but are not essential for the basic metabolic processes of the plant.

5. **Conclude the Answer**:
- Therefore, the answer to the question is that the substances produced by plants that have no apparent roles in growth and development processes are classified under the heading of **secondary metabolites**.