. Elementary biology; an introduction to the science of life . 2D: 2R 3D: IR Fig. 238. Mendel's Law of Segregation When two individuals with a pair of alternative characters are mated, the offspring will all have the character of one of the parents; this char- acter is called the dom'mant one, and the alterna- tive character is called the recessive. The hybrid offspring of such a mating is represented in the diagram by F-^. Offspring of this kind resemble the dominant parent Z), but experiments show that there is a real difference. If such a hybrid is mated with one of the pure dominant type,
. Elementary biology; an introduction to the science of life . 2D: 2R 3D: IR Fig. 238. Mendel's Law of Segregation When two individuals with a pair of alternative characters are mated, the offspring will all have the character of one of the parents; this char- acter is called the dom'mant one, and the alterna- tive character is called the recessive. The hybrid offspring of such a mating is represented in the diagram by F-^. Offspring of this kind resemble the dominant parent Z), but experiments show that there is a real difference. If such a hybrid is mated with one of the pure dominant type, /, the next generation will all appear dominant. If ' such a hybrid is mated with an individual of the recessive type, 2, the offspring will consist of dominants and recessives, in about equal num- bers. If two such hybrids are mated, j, the offspring will show both dominants and reces- sives, in the proportion of three to one. This splitting up of the offspring of hybrids into two types showing ancestral factors is almost universal; it is called segregation 1. He crossed hybrids with plants of the yellow- seeded parent variety. 2. He crossed hybrids with plants of the green- seeded parent variety. 3. He crossed hybrids with hybrids. The results of these crosses are indicated in Fig. 238. This fact of splitting up into the two ancestral types has been found to be quite general among all plants and animals that have been tested, and it is called the Law of Segre- eatioH. The idea is that the hybrid plant, no mat- ter how much it may re- semble one of the parents (with respect to one or more particular charac- ters), does not constitute a pure kind of organism, inasmuch as it cannot reproduce itself in off- spring all having the same character. The plants resulting from the mating of hybrids (that is, the segregated yellow-seeded and green-seeded individ- uals) were experimented withi
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