(i) How many true – breeding lines did Mendel select in pea plants for his experiments?

(ii) What is a true – breeding line?

(iii) Give two examples of contrasting traits studies by Mendel.

(i)Mendel selected 14 true breeding lines in his experiments.

(ii): True-breeding line refers to the one that have undergone continuous self-pollination and showed stable trait inheritance and expressions for several generations.

(iii): The examples of contrasting traits by Mendel are:

_• Cross pollinating a pure breed of Yellow(YY) and green(yy), in 1st filial generation all sends were yellow.In second filial generation he self pollinated and found 75%Yellow and 25%green pea seeds.

3rd flail generation he self pollinated and found 25%green(YY),50%green(Yy) and 25%yellow(yy).

so by this observed the Law of Dominance .

_• 2nd example is he crossed Tall and dwarf pea plants. he found that all the plants in F1 generation were tall.Thus it was dominant trait and dwarf was recessive trait.

In F2 generation, he observed that 3 of the offspring were tall and 1 was dwarf.

Mendel observed that in the F1 generation, the character of only one parent appeared whereas, in F2 generation, the characters of the other parent also appeared.

The characters that appeared in the F1generation are called dominant traits and those that appeared in F2 generation are recessive traits.