Long radishes were crossed with round with round radishes and produced all oval radishes.In the next generation, all three phenotypes of radishes-long, round, and oval- were present.
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Incomplete dominance occurs when one allele is not more dominant than the other. If we designate the genes (L=long, R=Round) then we have for the first cross all the radishes being heterozygous
RR (round radishes) x LL (long radishes)
= RL (oval radishes)
If these genes were complete dominance, then you would see the RL radishes either all long or all round depending on which one was dominant. For the second cross if you do a punnet square you will see:
1/4 RR (round)
2/4 or 1/2 RL (oval)
1/4 LL (long)
Again if these were dominant inheritance, you would see either 3/4 round or long (depending on which was dominant) and 1/4 would be the recessive, but since you see a combination that means that one gene is not more dominant than the other.
RR (round radishes) x LL (long radishes)
= RL (oval radishes)
If these genes were complete dominance, then you would see the RL radishes either all long or all round depending on which one was dominant. For the second cross if you do a punnet square you will see:
1/4 RR (round)
2/4 or 1/2 RL (oval)
1/4 LL (long)
Again if these were dominant inheritance, you would see either 3/4 round or long (depending on which was dominant) and 1/4 would be the recessive, but since you see a combination that means that one gene is not more dominant than the other.