MENDELIAN LAW OF UNIT CHARACTERS 



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fertilization of the eggs. Show the combinations of chromosomes in the 

 eggs. 



C. Draw in the representations of the chromosomes (beans). Color the 

 black and leave the white uncolored. How will you represent the hybrids ? 



H. Repeat the above experiment, using the hybrid combination of chromo- 

 somes in the primary sex cells. Keep in mind that primary sex cells can be 

 hybrid in regard to a particular character, but germ cells must be piu^Cc 



mature eg^s 



«^ mother cell 



' sperm mother cell 



A. Record combinations resulting from fertilizations. 



in. Repeat the experiment, using in the male primary sex cell the hybrid 

 combination, and in the female primary sex cell two recessive white chromo- 

 somes. Record by means of diagrams, the various possible combinations 

 resulting from fertilizations. 



IV. Repeat the experiment, using hybrid in one cell and dominant black in 

 the other. 



V. What law of heredity did experiment I illustrate ? What law of heredity 

 did experiments II, III, and IV illustrate? 



Mendelian Law of Unit Characters. Another important contri- 

 bution that IVIendel made was his emphasis upon the study of 

 single characters. In speaking of organisms, the general type is 

 referred to rather than the individual traits that make up that 

 type. Fox terrier, for example, or crimson rambler, describes a 

 complete picture without the need of hundreds of details in which 



