EXERCISE 101 



Many of the substances resulting from the metabolism in a cell (the chemical changes going on in 

 protoplasm) are injurious to protoplasm and must be removed if the cell is to continue living. In 

 many-celled organisms various structures and processes are related to excretion. 



In the table below enter in the appropriate spaces the names of the materials thrown out and the 

 structures and processes involved in excretion. 



EXCRETION FROM LIVING CELLS AND FROM ORGANISMS 



EXCRETED SUBSTANCES 



EXCRETING STRUCTURES AND PROCESSES 



Human being 



Cell of gray 

 matter in 

 spinal cord 



Apple tree 



Palisade cell 

 of leaf 



[108] 



