This Punnett square shows the crossing of two heterozygous plants with red flowers. R = dominant red, r = recessive white
The Punnett square is a chart used to predict an results of a genetic cross It is used to determine the probability of the occurrence of each genotype among offspring. The Punnett square shows every possible combination for a specific cross of maternal and paternal genotypes.
A. Dominant Allele
B. Recessive Allele
C. Homozygous White
D. Homozygous Red
E. Heterozygous Red
R, r, RR, Rr, rr
RR | Rr
----------------
Rr | rr
Genotype Ratios:
- 25% homozygous red (RR)
- 50% heterozygous red (Rr)
- 25% homozygous white (rr)
Phenotype Ratios:
- 75% red flowers
- 25% white flowers