A population of wild deer mice includes individuals with long or short hair. When two short haird indviduals breed, one-third of the pups have long hair. How do you explain the unusual phenotype ratio? Solution it can be autosomal inheritance where homozygous dominant is lethal. consider short hair to be dominant S, long hair to be recessive s so cross between two short haired can be Ss X Ss S s S SS Ss s Ss ss 1:2:1 ratio for SS:Ss:ss but we considered homozygous dominant to be lethal, so SS are dead, therefore Ss:ss is 2:1 and 1/3rd population have long hair..

1. A population of wild deer mice includes individuals with long or short hair. When two short
haird indviduals breed, one-third of the pups have long hair. How do you explain the unusual
phenotype ratio?
Solution
it can be autosomal inheritance where homozygous dominant is lethal.
consider short hair to be dominant S, long hair to be recessive s
so cross between two short haired can be
Ss X Ss
S s
S SS Ss
s Ss ss
1:2:1 ratio for SS:Ss:ss
but we considered homozygous dominant to be lethal, so SS are dead, therefore Ss:ss is 2:1 and
1/3rd population have long hair.