Answer to Question #292443 in Genetics for Smilynne

Question

10. When Mendel crossed a purple-flowered pea with a white-flowered pea in the P 

generation, all the offspring were purple, but the white flower trait reappeared in the 

F2 generation. How can a trait disappear in one generation and reappear in the 

next?

11. If you see a 3:1 ratio in the offspring from a genetic cross, what does this tell you 

about the genotypes of the parents?

12. If tall height (T) is dominant to short height (t) and purple flowers (P) are dominant 

to white flowers (p), what fraction of the offspring from the cross TtPp x ttPP will be 

short and purple?

 13. Let's you crossed a true breeding plant that produces lethal poison with a true 

breeding plant that produces no poison for the P generation. All of the F1 

generation produce mild poison. 1/4 of the F2 generation produce lethal poison, 1/4 

produce no poison, and 1/2 produce mild poison. What kind of dominance is this an 

example of?

Answer 1

10.Sometimes, when Mendel crossed two purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1 (purple-flowered pea plants to white-flowered pea plants).