1. In cucumbers orange fruit (R) is dominant to over cream fruit (r). A pure breeding orange cucumber is crossed with a pure breeding cream cucumber. The F1 are intercrossed to produce the F2.
a) Give the genotypes and phenotypes of the parents, F1, and F2.
b) Give the genotypes and phenotypes of the progeny if the F1 is backcrossed
i. To the orange parent
ii. To the cream parent
Pure breeding orange cucumber (RR) X Pure breeding cream cucumber (rr)
F1: Rr X Rr
Male/ female | R | r |
R | RR | Rr |
r | Rr | rr |
F2 progeny contain genotype RR (orange) Rr (orange) and rr (cream) in 1;2:1 or 3:1 rato
b)
F1 parent (Rr) back crossed with orange parent (RR)
male/ female | R | R |
R | RR | RR |
r | Rr | Rr |
The backcross results in 1:1 RR and Rr genotypes and both genotypes represent phenotype orange.
Fi parent (Rr) back cross with cream parent (rr)
male/ female | R | r |
r | Rr | rr |
r | Rr | rr |
The backcross results in genotypes Rr and rr in 1:1 ratio and phenotypes are orange and cream respectively.
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