PROBLEM 45 67 



Conclusion. — 1. How do you account for the presence of 

 carbon dioxide in the closed flask? 



2. Why did the seeds in the open flask grow ? 



3. From what source did the seeds get their energy to grow in 

 the open flask? 



General Conclusion. — Write up a brief statement, using proof 

 to show that energy is locked up in food and that it can be released 

 and used only by oxidation. 



Problem 43 : To study the fruit of the com plant. 



Materials. — Ripe corn on the cob. 



Method. — Compare the ripe corn on the cob with the picture 

 on page 67 of your Civic Biology and with specimens shown by 

 the teacher. 



Observations. — What differences are there between the young 

 and the old specimens ? 



Conclusion. — Is the ear of corn a single fruit or a bunch of 

 fruits? Give reasons for your answer. 



Problem 4=4: : To study the structure of a grain of com. 



Materials. — Entire soaked corn grains and some cut lengthwise 

 at right angles to the flat surface. Figure page 66, Civic Biology. 



Method and Observations. — In an entire corn grain find a 

 light-colored area on one side. Th's marks the position of the 

 embryo. 



In a grain cut lengthwise at right angles to the flat side find the 

 embryo. Describe its shape, position, and relative size compared 

 with the rest of the corn grain. 



KOTE. — The area outside of the embryo is known ag the endosperm. 



Place iodine on the surface of the cut corn grain. Describe 

 what happens. Test for protein. 



Conclusion. — 1. What nutrients are present in the corn? 

 2. Where are they found ? 



Problem. 45 : To find the use of the endosperm of the corn 

 grain. 



Materials. — Sprouted corn grains, scalpel, and sawdust. 



