134 BOTANY: PRINCIPLES AND PROBLEMS 



386. What is it that makes fats the most concentrated of foods? 



387. Why are proteins "far more effective than any other foods in 

 the construction and renewal of Hving substance?" 



388. Crops belonging to the Legume family usually contain more 

 protein than most crops. Explain. 



389. Where and when in a plant does digestion take place most 

 vigorously? 



390. What important difference is there between the process of diges- 

 tion in plants and that in animals? 



391. Just how does food which is stored in the endosperm of a seed, 

 and which is therefore not in the young embryo plant itself, become 

 available to this young plant? 



392. In what way do the insects captured by an insectivorous plant 

 become available to it as food? 



393. Why do parsnips taste so much sweeter in the early spring than 

 in the previous fall? 



394. Why are vegetables like peas and sweet corn much sweeter in 

 their young and immature state than when they grow older? 



395. Maple sap is very sweet in the spring but contains almost no 

 sugar in the summer. Explain. 



396. Hay harvested before its seed is ripe has much more feed value 

 than it has a few weeks later. Why? 



397. Certain fungi attack wood, their very delicate, thread-like 

 branches penetrating readily into the hard, woody tissues. How is it 

 possible for them to do this? 



398. Give three examples from every-day life (aside from those 

 mentioned in the text) of the conversion of kinetic into potential energy 

 and its subsequent release in kinetic form again. 



399. What is the ultimate source of all energy liberated in the bodies 

 of plants and animals? Explain. 



400. Just where in the plant body is kinetic energy changed into 

 potential energy and just where is potential energy changed into kinetic? 



401. What was the original source of the energy which we derive from 

 the burning of wood? Explain. 



402. What main sources of energy used by man in his industries owe 

 their origin to photosynthesis? What do not? 



