Which of the following statements is not correct?

Options

A. Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style
B. Insects that consume pollen or nectar without bringing about pollination are called pollen/nectar robbers
C. Pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil
D. Some reptiles have also been reported as pollinators in some plant species.

Answer

To determine which statement is not correct, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding the First Statement:**
- The statement says that pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style.
- **Analysis:**
- Pollen grains from different species can land on a stigma, but only the pollen of the same species as the flower can successfully germinate and grow a pollen tube. This part of the statement is correct.
- However, the first part of the statement is misleading because it implies that pollen from many species can germinate, which is not true. Only compatible pollen can germinate on a stigma.
- **Conclusion:** This statement is incorrect.

2. **Understanding the Second Statement:**
- The statement mentions that insects that consume pollen or nectar without bringing about pollination are called pollen or nectar robbers.
- **Analysis:**
- This statement is true. Insects that take nectar or pollen without facilitating pollination are indeed referred to as robbers.
- **Conclusion:** This statement is correct.

3. **Understanding the Third Statement:**
- The statement discusses that pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil.
- **Analysis:**
- This is also a true statement. The interaction between the pollen and the pistil is crucial for successful fertilization.
- **Conclusion:** This statement is correct.

4. **Understanding the Fourth Statement:**
- The statement claims that some reptiles have been reported as pollinators in some plant species.
- **Analysis:**
- This statement is true. While it is less common, certain reptiles can act as pollinators for specific plants.
- **Conclusion:** This statement is correct.

### Final Conclusion:
After analyzing all the statements, the first statement is the only one that is not correct. Therefore, the answer to the question is:

**Answer: The first statement is not correct.**