PLANT TRANSPORT

 

Plant Transport

1. How do mineral nutrients get into the vascular tissue of roots? How does water get into the vascular tissue of roots? What is the function of the endodermis? How does the structure of the endodermis allow it to perform its function?

 

2. What tissue transports water from roots to leaves? How does water get to the top of a plant? How does the structure of the water-transport tissue allow it to perform its function? Why can the water-transport tissue be dead and still perform its function?

 

3. Why do plants have stomates? By what mechanism are stomates opened and closed? How does the structure of guard cells allow them to perform their function? What environmental conditions will increase/decrease transpiration?

 

4. What tissue transports sugar (and water) in plants? How is sugar transported from leaves to other parts of a plant? How does the structure of the sugar-transport tissue allow it to perform its function? Why must the sugar-transport tissue be living?

 

5. You've cut a plant stem and you notice a small amount of sap on the cut stump. From where did this liquid come? Why?

 

6. Plants don't have transport systems for waste products. Why?

 

7. How are plant roots modified to perform their absorption function?

 

8. If you were to measure very carefully, you would find that the diameter of trees decreases slightly when conditions are warm and dry compared to when conditions are cool and moist. Why?

 

9. Although most plants open their stomates in the daytime and close them at night, some desert plants do just the opposite: they close their stomates in the daytime and open them at night. Why? How might these plants have to alter their photosynthetic machinery to accommodate this change in stomate function?

 

10. Overwatering is one of the most common houseplant problems. Why is overwatering bad for plants?

 

11. Fertilizers often come with the warning "Do not exceed recommended application rate." Shy would it be damaging to overfertilize a plant?

 

12. Far more species of insects feed on phloem sap (the solution transported in phloem) than on xylem sap. What is one difference between phloem and xylem that could account for this pattern in insect feeding? Explain.

 

13. It has been noted that when phloem-feeding aphids attack a plant, more sugar is sent to the area with the aphids than before the aphids attacked. How can this observation be explained by the mechanism of phloem transport?