PP-04 Complete Fill-in-the-Blanks Exercise

Water Transport Section:

1. Water potential equation: Ψw = _______ + _______ [Ψs, Ψp]
2. Ψs (solute potential) is always _______ or _______ [negative, zero]
3. Pure water has Ψw = _______ [0]
4. Water moves from _______ Ψw to _______ Ψw [higher, lower]
5. _______ is the movement of water through cell walls (apoplast). [Free diffusion/passive flow]
6. The apoplast pathway is blocked at the _______ by the _______ strip [endodermis, Casparian]
7. Casparian strip is made of _______ [suberin]
8. The symplast pathway uses _______ to connect cells [plasmodesmata]
9. Apoplast is _______ (faster/slower) than symplast [faster]
10. Root pressure is responsible for _______ [guttation]
11. Guttation occurs through _______ at leaf _______ [hydathodes, tips/margins]
12. The cohesion-tension theory was proposed by _______ and _______ [Dixon, Joly]
13. Transpiration creates _______ pressure in xylem [negative/tension]
14. _______ % transpiration is through stomata [90-95]
15. Guard cell _______ influx causes stomatal opening [$K^{+}$]
16. _______ (hormone) triggers stomatal closure [ABA]

Mineral Nutrition Section:

17. _______ essential elements are required by plants [17]
18. Macronutrients: _______ elements [9] needed in _______ amounts [large]
19. Micronutrients: _______ elements [8] needed in _______ amounts [trace/small]
20. Essentiality criteria were established by _______ and _______ [Arnon, Stout]
21. Mobile elements show deficiency in _______ leaves first [older]
22. Mobile elements: N, P, K, _______ [Mg]
23. Immobile elements show deficiency in _______ leaves first [younger]
24. Immobile elements: Ca, _______, S, Mn, B [Fe]
25. Central atom of chlorophyll: _______ [Mg]
26. Photolysis of water in PS II requires _______ [Mn]
27. _______ deficiency causes whiptail disease in cauliflower [Molybdenum/Mo]
28. _______ deficiency causes little leaf disease [Zinc/Zn]
29. _______ is essential for pollen germination [Boron/B]
30. _______ cofactor activates urease [Nickel/Ni]

Nitrogen Fixation/Cycle Section:

31. Biological nitrogen fixation converts _______ to _______ [$N_{2}$, $NH_{3}$]
32. Nitrogenase is a _______ protein requiring _______ ATP [Mo-Fe, 16]
33. Nitrogenase is irreversibly inhibited by _______ [$O_{2}$/oxygen]
34. Legume root nodule symbiont: _______ [Rhizobium]
35. Non-legume woody plant symbiont: _______ (organism in _______ and _______) [Frankia, Alnus, Casuarina]
36. Free-living aerobic $N_{2}$ fixer: _______ [Azotobacter]
37. Free-living anaerobic $N_{2}$ fixer: _______ [Clostridium]
38. Leghemoglobin scavenges _______ to protect nitrogenase [$O_{2}$]
39. Pink colour of root nodules is due to _______ [leghemoglobin]
40. Cyanobacterial $N_{2}$ fixation occurs in _______ cells [heterocysts]
41. Anabaena and Nostoc have _______ that lack _______ [heterocysts, PS II]
42. Nitrification step 1: $NH_{3}$ → $NO_{2}^{-}$ by _______ [Nitrosomonas]
43. Nitrification step 2: $NO_{2}^{-}$ → $NO_{3}^{-}$ by _______ [Nitrobacter]
44. Denitrification: $NO_{3}^{-}$ → $N_{2}$ by _______ [Pseudomonas]
45. Associative symbiotic $N_{2}$ fixer of grass rhizosphere: _______ [Azospirillum]