| A correct explanation for why tortoiseshell cats are almost always female and have a patchy distribution of orange and black fur might be that |
| | orange coat color is not found in male cats. | | black coat color is not found in male cats. | | tortoiseshell cats have two different X-linked alleles, X+ (black) and Xo (orange). Random X-inactivation during early development results in patches of orange and black. Males with only a single X chromosome will be either orange or black. | | tortoiseshell cats have two different X-linked alleles, X+ (black) and Xo (orange). Patchy coat coloration in females results from equal expression of both the X+ and Xo, with neither being completely dominant over the other. Males with only a single X chromosome will be either orange or black. | | None of the above choices are adequate explanations for why tortoiseshell cats are almost always females.
| |
| A correct explanation for why tortoiseshell cats are almost always female and have a patchy distribution of orange and black fur might be that |
| | orange coat color is not found in male cats. | | black coat color is not found in male cats. | | tortoiseshell cats have two different X-linked alleles, X+ (black) and Xo (orange). Random X-inactivation during early development results in patches of orange and black. Males with only a single X chromosome will be either orange or black. | | tortoiseshell cats have two different X-linked alleles, X+ (black) and Xo (orange). Patchy coat coloration in females results from equal expression of both the X+ and Xo, with neither being completely dominant over the other. Males with only a single X chromosome will be either orange or black. | | None of the above choices are adequate explanations for why tortoiseshell cats are almost always females.
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Answer:
tortoiseshell cats have two different X-linked alleles, X+ (black) and Xo (orange). Random X-inactivation during early development results in patches of orange and black. Males with only a single X chromosome will be either orange or black.
Black color due to inactivation of Xo, where as orange color is due to inactivation of X+, both color is resulted due to inactivation of X-linked genes.
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