Phenomena of Inheritance 



95 



RYT 



WGD 



FIG. 32. TRIHYBRID DIAGRAM SHOWING RESULTS OF CROSSING PEAS HAV- 

 ING ROUND-YELLOW SEEDS AND TALL STEM (RYT) WITH PEAS HAVING 

 WRINKLED-GREEN SEEDS AND DWARF STEM (WGD). Eight types of germ 

 cells are formed by the F x hybrid, as shown in the $ gametes above the 

 square and the $ ones to the left of it, and the possible combinations 

 (genotypes) of these $ and $ gametes are shown in the 64 small squares 

 of which only i is pure dominant (upper left corner), I pure recessive 

 (lower right corner) and 8 hqmozygotes (in diagonal line between these 

 corners). The relative numbers of the different phenotypes are 27 RYT: 

 9 RYD:g RGT: 9 WYT : 3 RGD : 3 WYD : 3 WGTn WGD. 



