To produce recessive white flowers from dominant red flower parents, one of the parents must be heterozygous (Rr), where R represents the dominant allele for red flowers and r represents the recessive allele for white flowers. If the other parent is homozygous dominant (RR), the expected genotype outcome from a cross (Rr x RR) would be:
- 50% Rr (heterozygous, red flowers)
- 50% RR (homozygous, red flowers)
In this scenario, both parents will produce red flowers and no white flowers will appear in the offspring.
However, if both parents were heterozygous (Rr x Rr), the expected genotypes would be:
- 25% RR (homozygous, red)
- 50% Rr (heterozygous, red)
- 25% rr (homozygous, white)
In this case, 25% of the offspring would be expected to have white flowers.
Thus, under typical genetic circumstances without other factors involved, the highest percentage of recessive white offspring the scientist can expect from dominant red flower parents (where one is heterozygous) is 25%.