EXERCISE 17 



DOES THE FORM AND STRUCTURE OF THE ROOT FAVOR 

 ABSORPTION? 



Materials. Low covered glass dish, as a petri dish, and clean filter 

 paper or blotting paper, or drinking glass and filter paper ; small 

 seeds, such as mustard, radish, clover, or wheat. 



Directions for work. Place a layer of blotting paper or several 

 layers of filter paper on the bottom of a dish and saturate it with 

 water. Sow seeds thinly on the wet paper and cover. Set in 

 a warm place several days, until the roots 

 of the germinating seeds have reached the 

 length of a half inch. 



If preferred, seeds may be sown in the 

 fold of a piece of filter paper, as illustrated 

 in the figure. It is necessary to provide 

 holes through the paper to allow the roots 

 to grow down into the water. These may 

 be made with a needle. 

 Examine the roots without exposing them to the air of the 

 room. Find and identify the root hairs. Note their abundance, 

 size, and distribution on the roots. Mount one of the root tips 

 on a slide and examine the root hairs with the compound 

 microscope, if possible. 



In what way might the root hairs aid in the absorption of 

 water ? 



References ' 



BERGEN and CALDWELL. Practical Botany, pp. 6-9. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 9, 10. 



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