Question: Purebred Pea Plant A is crossed with purebred pea plant B. It is found that the plants which look like A do not appear in Fl generation but re-emerge in F2 generation, which of the plants A and B are tall and dwarf?


a. A are tall and B are also tall
b. A are tall and B are dwarf
c. A are dwarf and B are tall
d. A are dwarf and B are also dwarf

Answer:
Answer: (c)

Plant ‘A’ and ‘B’ are purebred, which means they are homozygous. So, when they are crossed, all the plants in the F1 generation would be crossbred or heterozygous. Only the characteristic of a dominant trait is expressed in heterozygous condition. This means plant ‘B’ had dominant traits. Out of the characters ‘tall’ and ‘dwarf’, tall is dominant. So, plant ‘B’ was tall. Which also concludes that plant ‘A’ was a dwarf. The following would be the cross: