Questions and Problems 



107 



8. What is the method of inheritance of the human trait in the ac- 

 companying diagram? What is your reason? 



■-rO 



?r 





9. Suggest a method of inheritance for the trait in the accompanying 

 diagram and explain. 



D-rO O-rD 2>tO 



mcTrs^ 61 



10. In cats, gene b produces black fur and the allele B produces yellow. 

 The heterozygote has a peculiar fur called tortoise-shell. These genes are 

 in the X chromosome. What are the Fi and F2 from crosses between a 

 black female and a yellow male and a yellow female and a black male? 



11. If all black male cats were killed at birth, would tortoise-shell cats 

 be eliminated? Explain. Would black cats be eliminated? Explain. 



12. In Drosophila melanogaster , sable body (s) is recessive to wild 

 type (S). These genes are sex linked. What are the phenotypes and 

 genotypes from a cross between a homozygous wild-type female and a 

 sable male and from the reciprocal cross? 



