Mendel was lucky and could discover a law of heredity because he selected traits which
He chose garden pea that was easy to grow and to hybridise artificially. The pea plant is self-fertilising in nature, but it is easy to cross-breed experimentally. The plant reproduces well and grows to maturity in a single season.
Mendel then chose to follow seven visible features(unit characters), each represented by two contrasting forms or traits.
e)Mendel was fortunate in choosing a diploid plant because diploid organisms contain only two sets of chromosomes. If he had chosen a polyploid organism, an organism with, more than two sets of chromosomes, he would not have obtained simple, understandable results.
Through many generations of natural self-fertilization, garden peas had developed into pure line. A single alteration in a trait was therefore demonstrated by a visible difference between varieties.
He restricted his examination to one or very few pairs of contrasting traits in each experiment.
So, the correct option is 'Crossed independently’