Question

In a case of mammalian coat color, the principal gene identified is ${}^{\prime }{C}^{\prime }$ which codes for a tyrosinase enzyme. In case of rabbits four different phenotypes are observed.
Full Color > Chinchilla > Himalyan - Albino (in order of the expression of gene ${}^{\prime }{C}^{\prime }$ and its alleles). In a progeny obtained after crossing two rabbits, the percentages of Chinchilla, x-Hunalayan and Albino rabbits were $50,25$ and $25$ respectively What must have been the $C$ genotypes of the parent rabbits?

• A. $C^{ch}{C}^{ch}XC{h}^{ch}c$
• B. $C^{ch}{C}^{h}XC{h}^{ch}c$
• C. $C^{ch}cX{C}^{h}c$
• D. $C^h{C}^{h}X{C}^{ch}{C}^{ch}$

Answer 1

The correct option is C $C^{ch}cX{C}^{h}c$

We know that order of expression of genes hence dominance of alleles is in the order Full Color ( C ) > Chinchilla ( C${}^{ch}$ ) > Himalyan (C${}^h$ ) > Albino ( c ).

A cross between C${}^{ch}$c and C${}^h$c can bw depicted as -

Gametes	C${}^h$	c
C${}^{ch}$	C${}^{ch}$C${}^h$ ( Chinchilla )	C${}^{ch}$c ( chinchilla )
c	C${}^h$c ( Himalayan )	cc ( albino )

So, the correct option is 'C${}^{ch}$c×C${}^h$c'

illa ) C${}^{ch}$c ( chinchilla )

c C