Sun plants have

Options

A. (a) More mechanical tissues
B. (b) Extensive root system
C. (c) Abundant flowering
D. (d) All the above.

Answer

### Step-by-Step Solution:

1. **Understanding Sun Plants**: Sun plants, also known as heliophytes, are those that thrive in environments with high sunlight exposure. They require longer durations of sunlight for optimal growth and development.

2. **Characteristics of Sun Plants**:
- **Leaf Size**: Sun plants typically have smaller leaves. This adaptation helps reduce water loss through transpiration.
- **Branching**: They exhibit extensive short branching, allowing them to capture sunlight efficiently.
- **Surface Adaptations**: The leaves of sun plants are often hairy and have a waxy coating. This feature helps minimize transpiration loss, which is crucial given their high metabolic rates.
- **Mechanical Tissues**: Sun plants possess well-developed mechanical tissues, including a double layer of palisade parenchyma. This structure provides protection against intense sunlight and helps in photosynthesis.
- **Root System**: They have extensive shoot and root systems, which support their high metabolic needs and help in nutrient and water absorption.
- **Flowering**: Due to their developed physiology, sun plants tend to have abundant flowering.

3. **Examples of Sun Plants**: Common examples include mint and various varieties of roses, which require significant sunlight for their growth.

4. **Conclusion**: Based on the characteristics discussed, the options provided in the question can be evaluated:
- A) More mechanical tissues - Correct
- B) Extensive root system - Correct
- C) Abundant flowering - Correct
- D) All of the above - Correct

Thus, the correct answer is **D) All of the above**.