218 A YEAR IN SCIENCE 



12. When is this food used by the plant? 



13. Is this stored food of any value to us ? Explain 

 in what ways it is of value. 



14. How does the composition of proteins differ 

 from that of carbohydrates? 



15. "What are solutes? 



16. Explain what is meant by the process of 

 nutrition. 



17. Is it necessary for plants to digest their food? 



18. Define transpiration. 



19. State the disadvantages of transpiration. 



20. State the advantages of transpiration. 



21. Describe the general relation of plants to water. 



22. . How do plants living in water differ from those 

 living in a desert ? 



23. What are the principal ways in which plants are 

 protected against loss of water ? 



24. Is the loss of leaves in the autumn of any 

 advantage to plants? 



25. What causes the brilliant colors in leaves in the 

 autumn ? 



26. Why is it necessary for plants to breathe? 



27. What are the waste products formed in the 

 process of respiration ? Where are they given off from 

 the plant? 



28. How does the exchange of gases in respiration 

 in plants compare with that in animals ? 



29. Name plants in which air is stored. 



