Genetics! pls help! thank you very much?

in snapdragons, if red-flowered plants are pollinated by white-flowered plants, the offspring have pink flowers. Draw a Punnett swuare to show (a)result of crossing red-flowered and white-flowered plants and (b)then allowing their offspring to self-pollinate. what are the phenotype ratios in each case?



pls help.. i don't understand this question...

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Genetics! pls help! thank you very much?
Assume there is one gene for flower color:

R is the red allele

r is the white allele



RR is red

Rr is pink

rr is white



Crossing red(RR) and white(rr) flowers

.....R......R

r...Rr.....Rr

r...Rr.....Rr



All pink flowers

--------------------------------------...

The cross of two pink (Rr) flowers:

.....R.......r

R..RR...Rr

r...Rr.....rr



This gives a red:pink:white ratio of 1:2:1.
Reply:thanks for answering my question.. im sorry i wasn't able to pick a best answer coz i didn't have much time to decide.. but i was able to read your answer and use it... thanks a lot! Report It
Reply:It's an example of incomplete dominance (if you don't know that already, look it up and study some more).



R=Red

r=White



For this phenotypic ratio, I am using RR:Rr:rr, because it is incomplete dominance, as opposed to RR and Rr:rr, with a regular example



r r

R Rr Rr



R Rr Rr



It says that that all of this generation, known as F1(F for Filial), that all of the offspring will be pink, the phenotypic ration is 0:4:0



When allowed to self-pollinate, this Punnett square occurs,



R r

R RR Rr



r Rr rr



In this generation, known as F2, the phenotypic ratio is 1:2:1.