1. | two guard cells plus the subsidiary cells only. |
2. | an opening surrounded by two guard cells. |
3. | an opening surrounded by two guard cells and the subsidiary cells. |
4. | two guard cells only. |
1. | Generate secretory products to cause sting. |
2. | Reduce herbivory. |
3. | Bring about greater water loss through extended surface area of the epidermis. |
4. | Provide shade. |