EXERCISE 145 



When a parent is " pure " (either dominant or recessive) with respect to any character, all the germ 

 cells will carry the determiner for that one character ; but in a mixed, or hybrid, parent half the germ 

 cells will carry the dominant determiner and half will carry the recessive determiner. 



Problem. What are the chances of combining recessive and dominant determiners from two parents 

 Xhat are both of mixed composition ? 



What to use. Two bags, each containing 100 white beans to represent recessive (R) and 100 beans 

 that have been dipped in ink to represent dominant (D), well shaken up. 



What to do. Draw pairs of beans, one from each bag, sixteen times and record the drawings. 



FATHER 



MOTHER 



APPEARANCE OF OFFSPRING 1 



10 



11 



12 



13 



14 



15 



16 



1 If any dominant determiner is present, the offspring appears dominant ; if no dominant determiner is present, the offspring 

 appears recessive. 



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