EFFECT OF SUNLIGHT ON PLANTS 21 



of a week remove the pieces of cork and report how the 

 leaf appears. Let the leaf remain upon the tree and ex- 

 amine it at the end of another week. What has happened ? 

 b. Try other designs and remove the leaves from 

 the tree when the cork covers are removed. See who can 

 make the best design, 



Review Questions, 5. 



1. Which way does the Great Dipper move around 

 the North Star, clock-wise or the other way around? 



2. Look at the Great Dipper as early as you can see 

 it and as late as you can stay up, and see if you can tell 

 how many degrees it moves in one hour. 



3. If the sun rises exactly in the east and sets ex- 

 actly in the west, through how many degrees does it 

 move? How many hours does it take? 



4. At what hour does the sun rise when it rises ex- 

 actly in the east? Through how many degrees does the 

 sun move in one hour? 



5. Why does the sun appear larger at sunrise and 

 sunset than it does at noontime? 



6. Why does the sun appear red at sunrise and 

 sunset? 



7. Is it ever red at any other time? Why? 



8. What makes plants green? How can you show 

 this? 



9. When do plants grow best? Why? 



10. Did you obtain your answers to these questions 

 from books? What is the best way of obtaining these 

 answers? 



