How many of the following organic compounds found in organisms have no direct role in their normal growth and development but may have human welfare benefits ?
1. Alkaloids ,2. Flavonoids , 3 . Rubber , 4. Essential oils , 5. Antibiotics ,6 . Coloured pigments , 7. Scents 8. Spices

Options

A. 1 to 8
B. All except 5 and 8
C. 1,2,6 and 7 only
D. All except 1 and 5

Answer

To solve the question regarding how many of the listed organic compounds have no direct role in the normal growth and development of organisms but may have benefits for human welfare, we will analyze each compound one by one.

### Step-by-Step Solution:

1. **Alkaloids**:
- Alkaloids are plant-derived compounds that have significant medicinal properties. They do not play a direct role in the growth and development of organisms but are beneficial for human health (e.g., morphine, caffeine).
- **Conclusion**: Alkaloids have no direct role in growth and development but have human welfare benefits.

2. **Flavonoids**:
- Flavonoids are also derived from plants and are known for their antioxidant properties. They contribute to the flavor and color of foods but do not directly influence the growth and development of organisms.
- **Conclusion**: Flavonoids have no direct role in growth and development but have human welfare benefits.

3. **Rubber**:
- Rubber is a natural polymer obtained from the latex of rubber trees. It is primarily used in manufacturing products like tires and does not contribute to the growth or development of organisms.
- **Conclusion**: Rubber has no direct role in growth and development but has human welfare benefits.

4. **Essential Oils**:
- Essential oils are concentrated plant extracts used in aromatherapy, cosmetics, and food flavoring. They do not play a direct role in the growth and development of organisms.
- **Conclusion**: Essential oils have no direct role in growth and development but have human welfare benefits.

5. **Antibiotics**:
- Antibiotics are compounds that inhibit the growth of bacteria and are used to treat infections. They do not contribute to the normal growth and development of organisms.
- **Conclusion**: Antibiotics have no direct role in growth and development but have human welfare benefits.

6. **Coloured Pigments**:
- Colored pigments, such as carotenoids, provide coloration in plants and are often used as food colorants. They do not play a direct role in the growth and development of organisms.
- **Conclusion**: Colored pigments have no direct role in growth and development but have human welfare benefits.

7. **Scents**:
- Scents are derived from various plant sources and are used in perfumes and food flavoring. They do not have a direct role in the growth and development of organisms.
- **Conclusion**: Scents have no direct role in growth and development but have human welfare benefits.

8. **Spices**:
- Spices are used to enhance the flavor of food and have various health benefits. They do not contribute to the growth and development of organisms.
- **Conclusion**: Spices have no direct role in growth and development but have human welfare benefits.

### Final Count:
All eight compounds listed (1. Alkaloids, 2. Flavonoids, 3. Rubber, 4. Essential oils, 5. Antibiotics, 6. Coloured pigments, 7. Scents, 8. Spices) have no direct role in the normal growth and development of organisms but may have benefits for human welfare.

**Answer**: 8