. Adventures with animals and plants. Biology. 468 Orgmiisrns Are Fro ducts of Heredity and E?iviro?mief2t unit ix. Fig. 415 Bhie A7idalusian Fowl. These ''blue'''' {slate gray) Ajidalus'ian jowl are hy- brids containing a gene for blackness of feather and one for whiteness. Is this a case where contrast'ing colors do or do not blend? (snyder's principles of h£:redity) that showed in the hybrid, dominant, and the character that did not show he called recessive. He experimented with other contrasting characters in the garden pea and in every character he found no blending in the hybrids. He the
. Adventures with animals and plants. Biology. 468 Orgmiisrns Are Fro ducts of Heredity and E?iviro?mief2t unit ix. Fig. 415 Bhie A7idalusian Fowl. These ''blue'''' {slate gray) Ajidalus'ian jowl are hy- brids containing a gene for blackness of feather and one for whiteness. Is this a case where contrast'ing colors do or do not blend? (snyder's principles of h£:redity) that showed in the hybrid, dominant, and the character that did not show he called recessive. He experimented with other contrasting characters in the garden pea and in every character he found no blending in the hybrids. He therefore formulated his "law of ; More recent experiments show that in the majority of cases there is dominance when contrasting characters are crossed. There are numerous exceptions such as flower color in the four-o'clock and feather color in the Andalusian fowl. In crosses such as these where there is no dominance, there is blending inheritance or ificojnplete do7ni?ia//ce. Because there are exceptions we no longer speak of a law of dominance. Do Exercise 7 and if materials are available you will find Exercises 8 and 9 very interesting. Mendel's experiments with the garden pea. Among the seven pairs of contrast- ing characters which Alcndel studied in garden peas are these: tallness and short- ness, smoothness and wrinkledness of seed coat, yellowness and greenness of seed. In all of these experiments he started with plants that were pure for the particular character he was studying. He got pure plants by permitting the plants to self-pollinate for several genera- tions. If the offspring always bred true, that is, all had the same character as the parent, he was sure the plant was pure and not hybrid. When Mendel started with two pure parents, no matter what character he studied, the results were al- ways like those diagramed in Figure 416. Can you predict, by using diagrams, the results of a cross between plants with other contrasting characters? Try Exer
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