ISBN: 9781153629256

Excerpt: ...sex-factor. We may make a diagram of the kind given by Morgan if we use a rod of different shape for the female-producing sex-chromosome, and use the black rod for the dominan… More...

Excerpt: ...sex-factor. We may make a diagram of the kind given by Morgan if we use a rod of different shape for the female-producing sex-chromosome, and use the black rod for the dominant character:- BARRED female x unbarred male BX uY uX uX / / BX uX uY uX BARRED male unbarred female Heterozygous Homozygous BARRED male x unbarred female BX BX uX uY / / BX uX BX uY BARRED male BARRED female Heterozygous Heterozygous Another case is that of tortoise-shell, i.e. black and yellow cats. The tortoise-shell with very rare exceptions is female, the corresponding male being yellow, without any black colour. Doncaster found that a yellow male mated to a black female produced black male offspring and tortoise-shell females. When a black male is mated to a yellow female, the female kittens are tortoise-shell as before, but the males yellow. The Mendelian hypothesis which explains these results is that the male is always heterozygous, or has only one colour factor whether yellow or black, and transmits these colours only to his daughters, while the female has two colour factors, either BB, YY, or BY. Thus the crosses are:- YELLOW male x BLACK female YO male BB female / / YB female BO male Tortoise-shell female BLACK male BLACK male x YELLOW female BO male YY female / / BY female YO male Tortoise-shell female YELLOW male The sex must be determined therefore by the spermatozoa, as in the case of colour-blindness, etc., in man, and the colour factor must always be in the female-producing sperm. SEXUAL... J. T. Cunningham, Books, Science and Nature, Hormones And Heredity Books>Science and Nature The book has no illustrations or index. Purchasers are entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Subjects: Science / Life Sciences / Genetics<

ISBN: 9781153629256

Excerpt: ...sex-factor. We may make a diagram of the kind given by Morgan if we use a rod of different shape for the female-producing sex-chromosome, and use the black rod for the dominan… More...

Excerpt: ...sex-factor. We may make a diagram of the kind given by Morgan if we use a rod of different shape for the female-producing sex-chromosome, and use the black rod for the dominant character:- BARRED female x unbarred male BX uY uX uX / / BX uX uY uX BARRED male unbarred female Heterozygous Homozygous BARRED male x unbarred female BX BX uX uY / / BX uX BX uY BARRED male BARRED female Heterozygous Heterozygous Another case is that of tortoise-shell, i.e. black and yellow cats. The tortoise-shell with very rare exceptions is female, the corresponding male being yellow, without any black colour. Doncaster found that a yellow male mated to a black female produced black male offspring and tortoise-shell females. When a black male is mated to a yellow female, the female kittens are tortoise-shell as before, but the males yellow. The Mendelian hypothesis which explains these results is that the male is always heterozygous, or has only one colour factor whether yellow or black, and transmits these colours only to his daughters, while the female has two colour factors, either BB, YY, or BY. Thus the crosses are:- YELLOW male x BLACK female YO male BB female / / YB female BO male Tortoise-shell female BLACK male BLACK male x YELLOW female BO male YY female / / BY female YO male Tortoise-shell female YELLOW male The sex must be determined therefore by the spermatozoa, as in the case of colour-blindness, etc., in man, and the colour factor must always be in the female-producing sperm. SEXUAL... J. T. Cunningham, Books, Science and Nature, Hormones And Heredity Books>Science and Nature, General Books LLC<

ISBN: 9781153629256

Hormones and Heredity Paperback New Books, General Books