For his experiments on heredity, Mendel used :

How many pairs of constrasting characters in pea plants were selected by Mendel for his experiments on heredity ?

In his classic experiments on Pea plants, Mendel did not use

In his classic experiments on pea plants, Mendel did not use:

In his classic experiments on pea plants, Mendel did not use

In his classic experiments on pea plants, Mendel did not use