PLEASEEEE, help me for my biology! it makes me really confuse!!

In pea plants the colour of the peas is genetically controlled. Each pea represents a separate fertilisation. Smooth texture (S) is dominant to wrinkly (s) and green (G) colour is dominant to yellow (g). Following a breeding experiment with pea plants, the following ratio of pea phenotypes was found. Smooth and green : Smooth and yellow : wrinkly and green : wrinkly and yellow = 86 : 28 : 32 : 9. What is the most likely genotype of the parental plants?



a. SsGG and ssgg
b. SsGg and SsGg
c. SSGg and SsGg
d. SsGg and Ssgg

B is the answer because by looking at the phenotypes, all the phenotypes are present in the offspring, just not in even numbers. In order to have offspring of all four phenotypes (green, yellow, smooth, and wrinkled), both of the parents need to be heterozygous for both traits in order to preserve the traits in the offspring. That eliminates the rest of the answer choices.

The large number of smooth and green peas are due to the dominant allele, G and S. Even if the alleles are SSGG or SsGg or SSGg or SsGG, they all produce the same phenotype and thus, is the majority of the offsprings' phenotype.
However only ggss expresses the homozygous recessive phenotype for wrinkled and yellow. This concept also applies to the other phenotypes (smooth and yellow, wrinkly and green) which are low in numbers because only two recessive alleles make the trait recessive.

Hope this helped!

B is the correct answer. Since there is a majority of the dominant traits you can assume that both parents are dominant and carry the recessive. Since the recessive traits show you can immediately rule out A and C. Then with D since green is more likely than yellow you can safely eliminate D.