(d) What is in the soil that a root might take out?
(e) Why is nitrogen necessary, and how is it obtained?
Laboratory Suggestions
Demonstration.—Roots of bean or pea.
Demonstration or home experiment.—Response of root to gravity and to water. What part of root is most responsive?
Laboratory work.—Root hairs, radish or corn, position on root, gross structure only. Drawing.
Demonstration.—Root hair under compound microscope.
Demonstration.—Apparatus illustrating osmosis.
Demonstration or a home experiment.—Organic matter present in soil.
Demonstration.—Root tubercles of legume.