V. PLANT GROWTH AND NUTRITION. CAUSES OF 



GROWTH 



Problein. — What causes a young ])Iaiit to grow? 

 (a) The relation of the young ])Jant to its food suf)j)hj. 

 ib) The outside conditions necessary for germination. 

 (c) What the young ])lant does with its food supply, 

 id) How a plant or animal is able to use its food su])])ly. 

 (e) How a plajtt or animal prepaj^es food to use in various 

 parts of the body. 



Laboratory Suggestions 



Laboratory exercise. — Exainination 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 germination 

 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 em- 

 bryo 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. 



To THE Teacher. — One of the most essential reasons for placinK biology early 

 in the school curriculum is due to the fact that as an experimental science it makes 

 for straight thinking. If any one chapter in this book lends itself to logical devel- 

 opment, it is the chapter that follows. All laboratory work here outlined builds, 



bo 



