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17. 
18. 
19. 
20. 
BOTANY 
Draw roughly to scale the largest and the smallest leaf 
you know. 
How could you prove that a leaf has air spaces in it and 
air pores leading to the surface? 
Whence does a green plant derive the energy necessary 
to carry on its vital processes during periods of 
darkness? 
“What are the ‘‘veins’’ of a leaf? What are their uses? 
What experiment could you make in illustration? 
. Why are the inside leaves of a cabbage paler in colour 
than the outer ones? 
. Why do plants droop on a hot day and recover their 
freshness in the evening? 
. What are stipules? What purposes may they serve? 
Make drawings of three different leaves showing 
different types of stipules. 
. What is a stoma, and how does it work? 
. What advantage is gained by spraying the leaves of 
plants growing indoors or by a dusty road? 
. What are the essential characteristics of all foliage 
leaves? 
. What is chlorophyll and what purpose does it serve? 
. Why should a variegated bamboo not grow so vigorously 
as one which is green in all its parts? 
29. What are the chief external conditions that affect the 
rate of transpiration? 
. How would you obtain a solution of chlorophyll? 
. What is the potometer and how is it used? 
. Explain some of the different arrangements by which 
plants secure the maximum illumination for their 
leaves? Make illustrative drawings. 
- Enumerate the series of processes by which the nitro- 
genous compounds of plants are built up. What 
elements enter into these compounds? Whence does 
the plant obtain each of these elements? 
- What are the conditions essential to photosynthesis? 
- Under what conditions is chlorophyll replaced by etiolin? 
36. 
How would you prove that the different parts of a plant 
respire? At what periods in the life history of a plant. 
is respiration most vigorous? 
- What are cladodes and phyllodes? Under what circum- 
stances are they formed, and what advantage does the 
plant derive therefrom? 
