Here we are calculating the chances or probability of offspring from monohybrid cross (crosses involving just the one gene):
[this had already been covered in detail in 3.19]
Parents(phenotype)- Red Petals x White Petals
(genotype)- RR x rr R(dominant)>r(recessive)
The next stage involves meiosis in plants, its where they produce the pollen grains.
This shows us:
So there is a 100% chance that the offspring will have red petals (phenotype).
Lets breed two heterozygous flowers with red petals together.
Rr x Rr
the genotype of the random fertilisation is 25% RR, 25% rr, 50% Rr
the phenotype of the outcome is 25% white petals and 75% red petals.