PROIH.EM 2. The Part Ste?ris and Roots Flay in Making Food i6) 



Questions 



1. Draw in simple outline a taproot system and a fibrous root system. 

 Name several plants, the roots of which have large amounts of food. 



2. Name several plants which have roots above ground. 



3. What else makes up soil besides minerals? Name three substances 

 found in soil. What is soil water? 



4. Where are root hairs found? Describe their microscopic structure. 



5. What is diffusion? Explain how soil water enters a root hair. Re- 

 member to explain the movements of water and minerals separately. 



6. Why can diffusion into a root hair continue indefinitely? 



7. Name the three cylinders that make up the root, beginning with the 

 outermost. Where in the root is xylem found? Name two kinds of 

 cells that make up xylem. Where do you find phloem, sieve tubes, 

 and cambium? How do sieve tubes differ in structure from xylem 

 tubes? 



8. Draw and label a cross section of a stem, showing the cylinders 

 usually found. What makes up the vascular cylinder? Explain how 

 in many older stems the cortex is finally lost. 



9. How do stems grow in length? How do stems branch? 



10. Explain why one can count the rings of wood to determine the age 

 of a tree. Why must one count the rings at the base of the trunk? 

 In a table show the difference between the stems and leaves of the 

 monocots and dicots. 



11. Which substances pass through xylem tubes? Through sieve tubes? 

 In which direction is the passage in each kind of tube? 



12. When and where in plants is starch made soluble? 



13. What is capillary action? In which plant tissues does it occur? 



14. Define transpiration. Through which structures does water leave the 

 plant? What is the connection between transpiration and the rise of 

 water through the stem? 



15. Give some facts and figures to show that transpiration is important 

 to our lives. 



Exercises 



1. How do the roots of a young bean plant compare in extent with 

 the parts of the plant above ground? Uproot a voung bean plant raised 

 in sawdust and wash the root system clean. Measure the lengths of the 

 main stem and of the root. Now measure the spread of the longest 

 branches and of the longest side roots. Compare the total length of the 

 stems with that of the roots. Make a diagram to show the proportions. 



2. To learn the difference in size of particles in various kinds of soil, 

 place a trowel full of ordinary soil in a tall cylinder. Add water until 

 the cylinder is full. Stir thoroughly. Let stand until the particles have 



