Peas for every one wrinkled peawithin each pea pod of

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peas for every one wrinkled pea.Within each pea pod of this generation (a single pod contains about six to nine peas), about 75%, or three-quarters, of the peas were round, and about 25%, or one-quarter, were wrinkled (Figure 3-3). What happened when this second generation was allowed to grow and self-fertilize? Mendel planted both the round and wrinkled peas and observed that the wrinkled peas bred true, producing only wrinkled offspring. Likewise, approximately one-third of the round peas bred true, producing only round offspring.Two thirds of the round peas, however, gave rise to both round and wrinkled peas in the third, or generation. The results were similar for all seven paired characters. For every cross between parents showing alternate forms of a single trait, the offspring plants all exhibited just one form of the trait. When the plants underwent self-fertilization, about 75% of the resulting generation showed one form of the trait, and about 25% exhibited the alternate form (Figure 3-3). On the BioInquiry web site, you can try this experiment by crossing white-flowered peas and purple-flowered peas.What color are the blooms of the generation? Which form of the flower color trait occurs in about 75% of the generation? Mendel’s Interpretations Perhaps Mendel’s real genius was in how he interpreted the results of his experiments. Mendel imagined that each of the contrasting forms of a trait, for example the “roundness” or “wrinkledness” of seeds, was controlled by a hereditary factor. He realized that his results could be best explained by supposing these factors occur in pairs within the individual pea plants. A pea arising from a long line of plants producing only wrinkled seeds has two factors for wrinkled seed texture; likewise, a pea from a family lineage that produces only round seeds has two factors for round seed texture. When organisms breed, hereditary factors are passed on whole, and usually unal- tered,to the offspring.Mendel realized that during reproduction,each parent contributes one hereditary factor for each trait to the offspring.Thus for every trait, each individual has one maternally derived factor and one paternally derived factor—one factor from its mother and one from its father. F 2 F 1 F 2 F 1 F 1 F 3 , F 2 F 2 Monohybrid Cross: Experiment with the color traits of pea plants.
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3-1 How Are Traits Passed from Generation to Generation? 67 1 Mendel grew pea plants from true-breeding wrinkled-seeded and true-breeding round-seeded varieties. 2 When these plants matured, he used pollen taken from the anthers of the wrinkled- seeded variety to fertilize the plant grown from the round-seeded variety. He removed the anthers of the round- seeded plant to prevent self-fertilization.
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