MCB 259: PLANT PHYSIOLOGY 1998, Quiz 5
Name (please print):


1. EDTA is added to plant tissue culture media
A) as chelator of toxic heavy metals.
B) to keep iron ions in solution.
C) to complex iron in order to prevent its utilization by bacteria and fungi.

2. "Why" do plants roots secrete protons?
A) To avoid heavy metal poisoning
B) To prevent precipitation of some minerals in form of hydroxides
C) To increase the solubility of chelating compounds
D) To convert Fe3+ into Fe2+

3. Mycorrhizae is a term describing
A) the symbiosis of nitrogen fixing bacteria with some plants (root nodules)
B) Fungi in symbiosis with plants that fulfill some of the functions of root hairs
C) a fungal root infection that leads to the formation of crown galls (tumor growth)

4. What are the benefits that the mycorrhizal fungi gain from the association with the plant?



5. What is the name for the type of mycorrhizae in which the fungal hyphae do not enter the cells of the plant?



6. What is the name for the type of mycorrhizae in which the fungal hyphae do enter the cells of the plant?



10 7. What are the different functions of the root? (list at least four)



8. What are the functions of the root cap?



9. What is the quiescent center?



10. In which forms can nitrogen be taken up by the root? (give at least 3 options)



11. State Spenler's (Liebig's) minimum law in your own words:



12. Which elements are often limiting for plant growth?



13. Soils in tropical climates often have no or little ion exchange capacity. Why might that be a problem in agriculture? (Use back of page for your answer.)