To solve the question regarding the substances that need to be transported in flowering plants, we will analyze each option provided and determine their relevance to plant transport systems.
### Step-by-Step Solution:
1. **Identify the Substances to be Transported**:
- In flowering plants, various substances are essential for growth and development. These include:
- **Water and Mineral Nutrients**: Essential for photosynthesis, nutrient uptake, and overall plant health.
- **Organic Nutrients**: Such as sugars produced during photosynthesis, which are vital for energy and growth.
- **Plant Growth Regulators**: Hormones like auxins, cytokinins, and ethylene that regulate various physiological processes in plants.
2. **Understanding Transport Mechanisms**:
- **Short-Distance Transport**:
- Substances can move over short distances through **diffusion** and **cytoplasmic streaming**.
- **Active Transport** may also play a role in moving substances against their concentration gradient.
- **Long-Distance Transport**:
- For longer distances, plants utilize their **vascular system**, which consists of:
- **Xylem**: Transports water and minerals from the roots to the rest of the plant.
- **Phloem**: Transports organic nutrients, particularly sugars, from leaves to other parts of the plant.
- This process is known as **translocation**.
3. **Evaluate the Options**:
- Given the analysis, we can evaluate the options:
- **Water and Mineral Nutrients**: Yes, they need to be transported.
- **Organic Nutrients**: Yes, they are also transported.
- **Plant Growth Regulators**: Yes, these hormones are transported within the plant.
- Since all the mentioned substances are crucial for the plant's growth and development, the correct answer is that all of these substances need to be transported.
4. **Conclusion**:
- Therefore, the correct answer to the question is **"all of these"**.
### Final Answer:
All of these (water and mineral nutrients, organic nutrients, plant growth regulators) need to be transported in flowering plants.
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