Pollination basically refers to the transfer of pollen from the anther to the stigma . Pollination is of many types. The types of pollination depend on

Options

A. Shape of pollen grain
B. size of pollen grain
C. source of pollen grain
D. size of flower

Answer

To solve the question regarding the types of pollination and what they depend on, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Pollination**:
- Pollination is the process of transferring pollen from the anther (male part of the flower) to the stigma (female part of the flower). This is essential for fertilization in flowering plants.

2. **Identifying Types of Pollination**:
- Pollination can be classified into different types based on various criteria. The question provides four options to consider.

3. **Analyzing the Options**:
- **Option 1: Shape of pollen grain** - The shape of pollen grains does not significantly influence the type of pollination.
- **Option 2: Size of pollen grain** - Similar to shape, the size of pollen grains does not determine the type of pollination.
- **Option 3: Source of pollen grain** - This option refers to where the pollen comes from, which is crucial in classifying pollination types.
- **Option 4: Size of flower** - The size of the flower may affect accessibility for pollinators but does not classify pollination types.

4. **Classifying Pollination Based on Source**:
- Pollination can be classified into three main types based on the source of pollen grains:
- **Autogamy**: Transfer of pollen from the anther to the stigma of the same flower (self-pollination).
- **Geitonogamy**: Transfer of pollen from the anther of one flower to the stigma of another flower on the same plant (still self-pollination but between different flowers).
- **Xenogamy**: Transfer of pollen from the anther of one flower to the stigma of another flower of a different plant but of the same species (cross-pollination).

5. **Conclusion**:
- The types of pollination depend on the source of pollen grains. Therefore, the correct answer is **Option 3: Source of pollen grain**.