V. PLANT GROWTH AND NUTRITION. CAUSES OF 



GROWTH 



^ / 



Problem. What causes a young plant to grow? 



(a) The relation of the young plant to its food supply. 



(&) The outside conditions necessary for germination. 



(c) What the young plant does with its food supply. 



(d) How a plant or animal is able to use its food supply. 



(e) How a plant or animal prepares food to use in various 

 parts of the body. 



LABORATORY SUGGESTIONS 



Laboratory exercise. Examination of bean in pod. Examination and 

 identification of parts of bean seed. 



Laboratory demonstration. Tests for the nutrients : starch, fats or 

 oils, protein. 



Laboratory demonstration. Proof that such foods' exist in bean. 



Home work. Test of various common foods for nutrients. Tabulate 

 results. 



Extra home work by selected pupils. Factors necessary for germina- 

 tion of bean. Demonstration of experiments to class. 



Demonstration. Oxidation of candle in closed jar. Test with lime 

 water for products of oxidation. 



Demonstration. Proof that materials are oxidized within the human 

 body. 



Demonstration. Oxidation takes place in growing seeds. Test for 

 oxidation products. Oxygen necessary for germination. 



Laboratory exercise. Examination of corn on cob, the corn grain, 

 longitudinal sections of corn grain stained with iodine to show that embryo 

 is distinct from, food supply. 



Demonstration. Test for grape sugar. 



Demonstration. Grape sugar present in growing corn grain. 



Demonstration. The action of diastase on starch. Conditions neces- 

 sary for action of diastase. 



What makes a Seed Grow. The general problem of the pages 

 that follow will be to explain how the baby plant, or embryo, 



58 



