Question

Suppose that hybridization of a purple-flowered tall pea plant with a purple-flowered dwarf pea plant produced the following progeny:

Purple flowers, tall 58

Purple flowers, dwarf 64

White flowers, tall 15

White flowers, dwarf 21

Use the symbols A and a to represent the alleles that govern flower color and B and b to represent the alleles that govern plant height.

a) What are the genotypes of the parent plants and each of the different type of progeny?

b) Test the hypothesis that these genotypes are correct by using chi-square analysis.

Answer 1

flower la Purple plant CAA or Aal is dominant to white While Tall blant (BB or Bb) is dominant to small blant (bb) @ Genotypes of parent plantson Purple flower tall blant Aa Bb Purple flower dwarf plant Aa bb Genotype of progeny A.B. (3). A bb (3) aobo Gabbly. P - Aabb X Aabb. in Punnett square AB AB Ab ab - Ab AABB AaBb I AAbb i Aabbl - abl AaBb Gabb Aabb aabb) Purple, fall (A_B_) - (3); Purple, dwarf (A._bb) (3). while, tall Caa B-) . (1) ; white, dwarf (aabb) con 67 Expected ratio. 3:30 Chi-square testi Phenotyle observed (o) Expected (6) 10-626 Purple, tall 59.25 Purble, dwarf 64 59.25 while, tall 19.75 1.14 white, dwarf 21 19.75 12:1581 0,03 0.38 0.08 Tx² 1.631 valid As our calculated chi-square value (x²2 1.63) is lower than tabular value (7 841) at bad.o5 for 3 degree of freedom, our impothesis should be accepted to ou expected ratio is valid