Interestingly Aggiesrus same organism as described in questi
     Interestingly, Aggiesrus (same organism as described in question 2) females are the heterogametic sex with the sex chromosome genotype UC and males are the homogametic sex with the sex chromosome genotype CC. If a white-fur, short tail male is crossed to a yellow-fur, long tail female the following F1 are observed:  51 long-tail, yellow fur males  49 short-tail, yellow fur females  What are the parent and progeny genotypes based on the combined information given in question 2 and this question? (assume all parents are true breeding)  yytt male x YYTT female  YyTt males and Yytt females  yyC^t U male x YYC^T C^T female  YyC^T U males and YyC^t C^t females  YYC^t C^t males x yyC^T C^T female  YyC^T U males and YyC^t C^t females  yyC^t C^t males x YYC^T C female  YyC^t C^T males and YyC^t U females  yyC^t C^t male x YYC^T U female  YyC^t C^t males and YyC^T U females 
  
  Solution
Heterogametic female for UC
Homogametic male CC
White fur, short tail male yyCtCt x YYCTUyellow fur, long tail female [parents]
51 long tail yellow fur male YyCTCt and
49 short tail yellow fur female YyCtU [progenies]
If all parents are true breeding: Yellow(Y) color is dominant and Ct is recessive for long tail CT. the male should have CtCt because they are true breed and short tail. The long tail allele is not present in U chromosome.
So the option 4 is correct.

