l62 



EXAMINATION QUESTIONS. 



17. What is the cause of the ring- 

 like markings seen in the cross-section 

 of a tree-trunk? (S.K.E.) 



18. Descrihe and explain as much 

 of the texture of a deal plank as can 

 be made out with the naked eye. 

 (S.K.E.) 



19. Describe, with diagrams, the 

 primitive structure and the mode of 

 growth in thickness of the stem of a 

 dicotyledonous plant. "Why does the 

 stem of dicotyledonous plants usually 

 increase in thickness? (S.K.E.) 



20. Explain the modes by which 

 stems may increase in diameter. Point 

 out the causes of the difference be- 

 tween the spring and the autumn wood 



of dicotyledonous trees with annual 

 growth. (S.K.A.) 



21. Explain the difference in the 

 growth of the bark of a tree and that 

 of the wood. (S.K.E.) 



22. What is the structure of the 

 cambium ; how does it originate in 

 the stem, and to what tissues does it 

 give rise? (S.K.A.) 



23. From what source is the starch 

 derived which is stored up in a potato 

 tuber? By what means has it been 

 transported thither ? (S.K.E.) 



24. State what is the tissue in which 

 water travels from the root to the 

 leaves, mentioning illustrative experi- 

 ments. (S.K.E.) 



3. Foliage Leaf. 



25. Describe a bud. To what struc- 

 tures do the outer coverings corre- 

 spond? What is the origin and use of 

 the resinous secretion witli which they 

 are often covered? (S.K.E.) 



26. How do the outer leaves of a 

 bud generally differ from the inner? 

 (S.K.E.) 



27. What is a leaf? What is its use 

 to the plant? (S.K.E.) 



28. Of what parts is a leaf made up? 

 What is the use of the leaf as a whole, 

 and what are tbe uses of the several 

 parts? (S.K.E.) 



29. Give instances of foliar organs 

 in which only the part corresponding 

 to the petiole of the leaf is developed. 

 (S.K.A.) 



30. Describe the nature of stipules, 

 and illustrate from British plants the 

 forms which these organs may assume. 

 (S.K.A.) 



31. What are stipules ? Describe the 

 stipules of the rose and of the sweet- 

 pea. (S.K.E.) 



32. What is the general plan of ar- 

 rangement of leaves on a stem? Why 

 is it the most advantageous to the 

 plant? (S.K.E.) 



33. Give instances in which leaves 

 are only imperfectly developed. What 

 useful purposes may they serve in such 

 cases? (S.K.E.) 



34. Mention, with examples, special 

 purposes to which leaves are adapted 

 in different plants. (S.K.A.) 



35. Describe the structure of an 

 onion. (S.K.E.) 



36. What is the use of the leaf to an 

 ordinary green plant? (L.M.) 



37. What components of the atmos- 

 phere are taken from it by plants, and 

 for what purpose ? (S.K.E. ) 



38. From what source does a green 

 plant obtain its carbonaceous food, and 

 in what form and by what organs does 

 it absorb it? What are the conditions 

 upon which the assimilation of the car- 

 bonaceous food depends? (S.K.E.) 



39. Plants are said to "starve in the 

 absence of light." Explain this state- 

 ment. (S.K.E.) 



40. State why absence of light is in- 

 jurious to plants. (S.K.E.) 



41. Explain what is meant by trans- 

 piration, and state how this process 

 mav be experimentally demonstrated. 

 (S.K.E.) 



42. What is meant by transpiration ? 

 Under what circumstances do plants 

 transpire most? (S.K.E.) 



43. Explain why it is that plants 

 droop on a hot day, and recover their 

 freshness in the evening. (S.K.E.) 



44. Describe the structure, develop- 

 ment, aud mechanism of the stomata. 

 What is the effect of exposure to light 

 upon the stomata? (S.K.A.) 



45. A withered branch on a tree with 

 deciduous leaves retains its leaves in 

 winter when the living branches have 

 lost theirs. Explain the reason of this. 

 (S.K.A.) 



46. When a branch is cut off a plant, 

 the leaves upon it shortly begin to droop. 

 Explain why this happens. (S.K.E.) 



