GRADE VIII.
(Woodworking Group VII.)
Lesson 23.
Recitation—
Respiration is another name for breathing. How does it apply to plants?
Animals breath in oxygen and breath out carbonic acid gas.
How about plants?
Carbonic acid gas is poisonous. Is it harmful to have plants in the house? Explain.
How do trees breathe?
Transpiration? What is it and where and why does it take place?
What per cent. of living cell is water? Where is the water contained?