. Readings in evolution, genetics, and eugenics. Evolution; Heredity; Eugenics. 438 READINGS IN EVOLUTION, GENETICS, AND EUGENICS breeding true for a sex-linked character, the female is homozygous for the character in question while the male is heterozygous and incap- able of becoming homozygous. Reciprocal crosses with such a race give unhke results, because the female transmits the character to all her offspring, but the male transmits it to only half his offspring, viz., the Fig. 91.—Sex-linked inheritance of barred and unbarred (black) plumage in poultry. P, parents, barred male,
. Readings in evolution, genetics, and eugenics. Evolution; Heredity; Eugenics. 438 READINGS IN EVOLUTION, GENETICS, AND EUGENICS breeding true for a sex-linked character, the female is homozygous for the character in question while the male is heterozygous and incap- able of becoming homozygous. Reciprocal crosses with such a race give unhke results, because the female transmits the character to all her offspring, but the male transmits it to only half his offspring, viz., the Fig. 91.—Sex-linked inheritance of barred and unbarred (black) plumage in poultry. P, parents, barred male, unbarred female; Fi, barred males and females; Fj, males all barred, females in equal numbers barred and unbarred. {After Morgan.) 2. Poultry tj^e.—^Another type of sex-linked inheritance exists in which the sex relations are exactly reversed. This was first observed in the moth. Abraxas, but more famihar cases occur in poultry, for which reason it may be called the poultry type of sex-lmked inherit- ance. Here the male is the homozygous sex, the female being hetero- zygous. This condition is found in moths and in certain birds, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Newman, Horatio Hackett, b. 1875. Chicago : University of Chicago Press
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherchica, bookyear1921
