Question

you have two pure-bred varieties of roses, one that has multiple flowers on each stem and red petals, and another that has one flower per stem and yellow petals. you are sure you could get rich if you could just get a multiple-flowered, yellowfins petalled rose bush. you cross your two pure breeding varieties and all the F1 progeny plants have identical phenotype, but your lab assistant forgets to write down the phenotype and then loses the plants. fortunately, you still have one hundred F2(progeny from self-crossing the F1 hybrids before they were lost), and you find the F2 phenotypes as follows:

19 single-flowered red,

18 multi-flowered yellowfins,

8 single-flowered yellowfins,

55 multi flowered red.

a) which phenotypes are dominant

b) record the ratio of the F2 offspring and list the genotypes and phenotypes associated with each number in the ratio

Answer 1

a) Dominant phenotypes-multiple flowers on stem & red petals.

Because out of 100 , 55 progenies are multi flowered red plants.

b)

Phenotypic ratio= 9:3:3:1

Genotypic ratio= 1:2:1:2:4:2:1:2:1

Hope you got it.

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