Questions and Problems 479 



of all three species. Show how such trispecific tetraploids might have 

 arisen. 



2. Which should be easier: (a) to obtain triploids if you have only 

 tetraploids and diploids or (6) to obtain tetraploids if you have only 

 triploids and diploids? 



3. Which should be easier: (a) to obtain triploids if you have only 

 tetraploids or (b) to obtain tetraploids if you have only triploids? 



4. If a chemical could be found that is as successful in producing 

 haploids as colchicine is in producing polyploids, how could homozygous 

 true-breeding strains be developed rapidly? 



