Among dogs, short hair is dominant to long hair and dark coat color is dominant to white (albino) coat color. Assume that these two coat traits are caused by independently segregating gene pairs. For each of the crosses given below, write the most probable genotype (or genotypes if more than one answer is possible) for the parents. It is important that you select a realistic symbol set and define each symbol below.
Parental Phenotypes Phenotypes of Offspring
Short Long Short Long
Dark Dark Albino Albino
(a) dark, short × dark, long 26 24 0 0
(b) albino, short × albino, short 0 0 102 33
(c) dark, short × albino, short 16 0 16 0
(d) dark, short × dark, short 175 67 61 21
Assume that for cross (d), you were interested in determining whether fur color follows a 3:1 ratio. Set up (but do not complete the calculations) a Chi-square test for these data [fur color in cross (d)].

Answer :

Complete question:

Among dogs, short hair is dominant to long hair and dark coat color is dominant to white (albino) coat color. Assume that these two coat traits are caused by independently segregating gene pairs. For each of the crosses given below, write the most probable genotype (or genotypes if more than one answer is possible) for the parents. It is important that you select a realistic symbol set and define each symbol below.

 Parental Phenotypes                         Phenotypes of Offspring    

                                                            Short     Long   Short     Long  

                                                            Dark     Dark   Albino   Albino

(a)  dark, short × dark, long                26          24         0            0  

(b)  albino, short × albino, short          0            0         102        33  

(c)  dark, short × albino, short            16            0          16           0  

(d)  dark, short × dark, short               175         67         61          21

Assume that for cross (d), you were interested in determining whether fur color follows a 3:1 ratio. Set up (but do not complete the calculations) a Chi-square test for these data [fur color in cross (d)].

Answer:

(a) DDSs   x     DDss

     DDSs   x     Ddss

(b) ddSs   x     ddSs

(c)  ddSS   x     DdSS

     ddSs   x     DdSS

     ddSS   x     DdSs

(d)  DdSs     x       DdSs

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Chi square = X² = ∑ ((O-E)²/E) = ((242 - 243)² / 243) + ((82 - 81)² /81) = 0.0164  

Explanation:

Due to technical problems, you will find the complete explanation in the attached files

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