Final answer:
Approximately 75% of the F2 generation plants will have yellow seeds due to the dominant allele for yellow seed color, following the 3:1 Mendelian ratio of yellow to green phenotypes.
Step-by-step explanation:
In the context of Gregor Mendel's classic genetics experiments with pea plants, when F1 generation plants with yellow and round seeds are self-pollinated, their offspring (the F2 generation) exhibit different combinations of seed color and form. According to Mendel's observations, there is a 3:1 ratio of yellow to green seeds in the F2 generation. This ratio is the result of the dominant yellow seed color allele masking the effect of the recessive green seed color allele.
To calculate the proportion of yellow seeds in the F2 generation, we examine the predicted phenotypic ratio. Among the F2 offspring, 3/4 will have yellow seeds, as yellow is the dominant trait. Therefore, if we have a large number of F2 offspring, approximately 75% of them are expected to exhibit the yellow seed coloration.
For example, if 100 F2 generation plants are produced, around 75 of them would have yellow seeds because of the 3:1 phenotypic ratio of yellow to green that Mendel outlined in his experiments. This is further supported by calculations like Punnett square analysis which are based on Mendelian genetics principles.