In red foxes (Vulpes vulpes), the sex of the offspring is determined by the inheritance of sex chromosomes X X\,X and Y Y\,Y in the same way as in humans.
Female Gamete 1Female Gamete 2Male Gamete 1Offspring POffspring QMale Gamete 2Offspring ROffspring S\begin{array}{c|cc} & \text{Female Gamete 1} & \text{Female Gamete 2} \\ \hline \text{Male Gamete 1} & \text{Offspring P} & \text{Offspring Q} \\ \text{Male Gamete 2} & \text{Offspring R} & \text{Offspring S} \end{array}Male Gamete 1Male Gamete 2Female Gamete 1Offspring POffspring RFemale Gamete 2Offspring QOffspring S
Identify:
The genotypes of the female gametes and male gametes.
The genotypes of offspring P, Q, R, and S.
A female fox has a litter of 6 cubs. Explain why there might be 5 male and 1 female cubs, rather than exactly 3 of each.