WAEC Biology 2015 Papers

Concept:The skin colour gene has two alleles: $H$ for spotted and $h$ for black. Since a black panther shows the recessive trait, its genotype must be $hh$.Explanation:The diagram shows a cross that produces spotted and black offspring in a $1:1$ ratio.A spotted leopard crossed with a black panther can produce this ratio only if the spotted leopard is heterozygous, $Hh$, and the black panther is homozygous recessive, $hh$.The cross is represented as:$$Hh \times hh \Rightarrow Hh : hh = 1:1$$Therefore, the spotted leopard has genotype $Hh$ and the black panther has genotype $hh$.Answer:Spotted Leopard: $Hh$; Black Panther: $hh$Correct option: D