The shape of pollen grains is generally and measure about ______`mu` m in daimter:

Options

A. Spherical, 100 - 200
B. Rod shaped, 25 - 50
C. Triangular, 1000 - 2000
D. Spherical, 25 - 50

Answer

### Step-by-Step Solution:

1. **Identify the Shape of Pollen Grains:**
- Pollen grains are generally described as having a **spherical shape**. This is a common characteristic across many species of flowering plants.

2. **Determine the Diameter of Pollen Grains:**
- The diameter of pollen grains typically ranges from **25 to 50 micrometers** (µm). This measurement indicates that pollen grains are quite small, which is important for their function in plant reproduction.

3. **Fill in the Blanks:**
- Based on the information gathered, we can fill in the blanks in the question:
- The shape of pollen grains is generally **spherical** and measure about **25 to 50 µm** in diameter.

### Final Answer:
The shape of pollen grains is generally **spherical** and measure about **25 to 50 µm** in diameter.

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