CHAPTER VI 



TYPICAL 

 ANIMAL CELL 



Photomicrographs of Amoeba 



and of Paramecium. 



Do animals ever consist of single cells ? Can the simplest of animals 

 be easily recognized as animals ? Do they appear different from one- 

 celled plants? Do they perform the same physiological activities f 



Laboratory exercise. Study of an amoeba (amoibos changing). The 

 amoebas belong to the branch of animals called Protozoa (protos first ; zoon 

 animal : first or early animal). To locate amoebas, scrape the undersurface of 

 the leaves of Elodea on to a glass slide. Add a drop of water and cover with a 

 cover glass. Another method for finding amoebas is to crush some pond lilies 

 or other water plants and let the mass remain undisturbed for a few weeks. 

 Tiny animals will usually be found in the scum which forms. Mount some of 

 the scum and locate an amoeba with low power, then study it with high 

 power. Later stain with iodine and again observe. 



I. Describe the amoeba, including shape, color, and number of cells. 



II. How does its shape differ from any cell previously observed? The 

 irregular projections of protoplasm are called pseudopodia or pseudopods 

 (pseudo false; podium foot). What seems to be the function of the 

 pseudopodia or false feet ? 



III. Describe the movement of the animal. Suggest a reason for the 

 name amoeba. 



IV. After staining it with iodine, find cytoplasm, nucleus, and a space 

 called the contractile vacuole. The clear outer protoplasm of the cell is called 

 ectoplasm and the granular inner area is endoplasm. 



V. State three structures found in the Spirogyra not found in the amoeba, 

 and one structure found in the amoeba not found in the Spirogyra. 



VI. State a difference in nutrition between Spirogyra and amoeba. 



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