The chemical responsible for fossilisation of pollen grains is

Options

A. Sporopollenin
B. Pollenkit
C. Lignin
D. Carotenoids

Answer

To answer the question regarding the chemical responsible for the fossilization of pollen grains, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Components of Pollen Grains**:
- Pollen grains have an outer covering known as the exine. This exine is crucial for the protection of the pollen grain.

2. **Understand the Role of Sporopollenin**:
- The exine is primarily made up of a substance called sporopollenin. This is a chemically inert polymer that provides significant resistance to degradation.

3. **Recognize the Importance of Resistance**:
- The chemical inertness of sporopollenin helps protect pollen grains from environmental factors, including enzymes that could lead to degradation.

4. **Evaluate the Other Options**:
- **Pollen Kit**: This is a sticky oily covering found on the surface of pollen grains but does not contribute to fossilization.
- **Lignin**: While it may be present in some plant structures, it is not specifically responsible for the fossilization of pollen grains.
- **Carotenoids**: These are pigments and do not play a role in the fossilization process of pollen.

5. **Conclude the Correct Answer**:
- Based on the information gathered, the chemical responsible for the fossilization of pollen grains is **sporopollenin**.

### Final Answer:
The chemical responsible for the fossilization of pollen grains is **sporopollenin**.

---