Question

a) In radishes, the plants can be tall (allele T) or dwarf (allele t). Tall is dominant. Root color can be red (allele R^R), white (allele R^W), or pink (heterozygote). A radish that is true-breeding for both red roots and tallness (R^RR^R TT) is crossed with a radish that is true-breeding for both white roots and being dwarf (R^WR^W tt).  Write the genotype and phenotype for the F1 generation.

b) Assume the two genes for plant height and root color are on separate chromosomes. Two plants from the F1 generation are crossed with each other to produce the F2 generation. Use a Punnett square to show the dihybrid cross and the genotypes of the F2 generation. What will be the phenotypic ratio for the F2 generation?

please answer question b.

Answer 1

As the root colour alleles are incompletely dominant, the F2 phenotype ratio changes to

RWR W tt a) Parent Gamete RRRR TT RRD RWA F Genotype - Phenotype Pük, Tall F RT T Ret RW RWD RRRR TI I RRRR TE RR RW IT RRR" It Red, Tall Red, Tall Pink, Tall Punk, Tall RRRR TE RR RR it | RR Rw It R RH Red, Tall Red Dwarf Pink, Tall Pink, Dwarf RRR TTR Rw It I RNRW TT RR It Pink, tall Pink Tall allite, Tall White, Tall! RAW TE R r th Rw pw It RR tt Dink Tall I Dink, Dwarf allite, Tall white, Swand BWT Que Phenoty Thenotype reafio - 3 , ' . 6 . 2 . 3 . ched Tal)" Red, Duvard)Paul, Tall: Cricke, Danse) Wallite, balloCilate Candy

3 (red,tall): 1 (red,dwarf): 6 (pink,tall): 2 (pink,dwarf): 3 (white,tall): 1 (white,dwarf).

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