88 
19. 
24. 
BOTANY 
What are surface-feeders, deep-feeders? How are the 
two classes able to live together in a forest? 
. What is meristem? How do plants grow? 
. How would you show the region of elongation in root and 
stem ? 
. What are tropisms? What are the chief factors govern- 
ing the tropisms of roots? 
. Compare the tropisms of the root with those of the stem. 
. How do water, gravity, and light affect the direction of 
root growth ? What is the eclinostat? 
. What is the use of the root-cap? 
. What is the advantage of root-hairs to a plant, and what 
is the advantage of their clinging so closely to the soil- 
grains? 
. What gas is formed by the roots? What is root acid, and 
what is its use? 
. Make drawings showing the different types of roots. 
. For what purposes other than food-absorption may roots 
be used? Give examples and make drawings. 
. In what forms are the reserves of food accumulated in 
* roots? What purpose is served by these reserves? 
. Describe the internal structure of a root. How do branch 
roots arise? 
. How do green plants obtain nitrogen? 
. What are the essential foods obtained by a plant from 
the soil? What experiments would you make in 
illustration ? 
What advantage is it to a plant that the root responds to 
the stimulus due to moisture more readily than to that 
due to gravity? 
. How is the direction of a root’s growth affected by light? 
How does a shoot differ from a root in this respect? 
- How is the growth of a root-tip affected by contact with 
a hard obstacle? 
- Mention some of the ways in which weeds are injurious 
to crops. 
- Show how such gardening operations as digging, 
manuring, raking, transplanting, and watering may be 
best carried out to minister to the needs of the plant. 
What is ‘‘water-culture’’? Give a list of the substances 
used in making up a culture-solution for a green plant. 
