Question

Pure bred pea plants A are crossed with pure bred plant B . It is found taht the plants which look like A do not appear in F1 generation but re emerge in F2 generation. Which of the plants A are B are 1. Tall and 2. Drawf?Give reason

Answer 1

A is dwarf coz in f1 generation the hybride is Tt that is tall and it is given in question that plants which look like a do not appear in f1 generation

Answer 2

Plant A is dwarf and plant B is tall

Explanation:

The plants appear in F1 generation donot resemble to Plant A because it is dwarf plant and this character is controlled by recessive genes which can express themselves only in homozygous condition.

                    However, The plant B is tall which has dominant genes that can express themselves in homozygous or heterozygous state.

Now the organisms produced in F1 generation after the cross between Pure A and Pure B  will be tall with genotype Tt ( heterozygous). That is why dwarf character does not appear .

Hence F1 generation lacks plant with trait like plant A .

In F2 , As the 50% population of organisms is hybrid Tt and 25% will be TT and 25% will be tt . That is why dwarfness appear in f2 generation