in a pea plant,smooth seed coats is dominant over wrinkled seed coat. what will be the expected ratio of phenotypes of the offspring in a cross between-

1.heterozygous smooth and heterozygous smooth

2.heterozygous smooth and heterozygous wrinkled

3.heterozygous smooth and homozygous smooth

(i) When a cross is made between two heterozygous smooth plants, the phenotypic ratio of offsprings will be 3:1 means three offsprings will have smooth seed coat whereas one offspring will have wrinkled seed coat.

(ii) This cross is not possible because wrinkle trait is recessive & it cannot express itself in heterozygous condition. It always need homozygous condition for its expression(ww).

(iii)When a cross is made between heterozygous smooth and homozygous smooth, all offsprings with smooth seed coat are produced. 

  • 6

2. 1:1

3. 2:1

  • -7
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