Predict the phenotypic and genotypic ratios of the offspring from a cross between a tortoiseshell female cat and an orange male cat.

Male kittens have only one X chromosome ($\text{XY}$). To express the tortoise-shell colour, an individual needs to have both the $\text{X}^{\text{B}}$ (black) and $\text{X}^{\text{O}}$ (orange) alleles. Since males only inherit one X chromosome, they can only carry one fur colour allele ($\text{X}^{\text{B}}$ or $\text{X}^{\text{O}}$), making it impossible for them to be tortoise-shell.

Female kittens have two X chromosomes ($\text{XX}$). This allows them to inherit one $\text{X}^{\text{B}}$ allele on one X chromosome and one $\text{X}^{\text{O}}$ allele on the other X chromosome, resulting in the genotype $\text{X}^{\text{B}}\text{X}^{\text{O}}$. The expression of both alleles due to random X-inactivation in different cells leads to the tortoise-shell pattern.