Plants adapted to low light intensity have

Options

A. higher rate of `CO_(2)` fixation than the sun plants
B. more extended root system
C. leaves modified to spines
D. larger photosynthetic unit size than the sun plants

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the characteristics of plants that are adapted to low light intensity.

2. **Identifying Plant Types**: Recognize that plants have varying light requirements. Some plants thrive in low light (shade-loving plants), while others prefer bright sunlight.

3. **Characteristics of Shade-Loving Plants**:
- Shade-loving plants typically have **dark green leaves**. This is due to a higher concentration of chlorophyll, which is essential for photosynthesis.
- The increased chlorophyll content allows these plants to capture more light, even in low-light conditions.

4. **Photosynthetic Unit Size**:
- Plants adapted to low light intensity have a **larger number of photosynthetic units** (PSUs) compared to plants that grow in bright sunlight. This adaptation helps them maximize light capture for photosynthesis.

5. **Conclusion**: Therefore, the main characteristic of plants adapted to low light intensity is that they have a **higher chlorophyll content** and a **larger photosynthetic unit size** than sun-loving plants.

6. **Correct Option**: Based on the analysis, the correct answer to the question is that plants adapted to low light intensity have a **larger number of photosynthetic units**.