State the reasons for Mendel's success.

Which of the following pea plants will always produce white flowers?

Consider the following four statements $I, II, III$ and $IV$ and select the correct statement:
$I.$ Mendelian experiments have a large sampling size, which gave greater credibility to the data that he collected.
$II.$ Recessive allele influences the appearance of the phenotype even in the presence of a dominant allele.
$III.$ Mendel analysed qualitative characters in garden pea.
$IV.$ In $F_2$-generation of a Mendelian monohybrid cross, the tall and dwarf traits were identical to their parental types and show no blending inheritance.

How many pairs of true-breeding pea plant varieties were selected by Mendel,which were identical except for one character with contrasting traits?

How many traits of the pea pod were studied by Mendel?

Based on Mendel's experiments,explain the concepts of factors,dominant/recessive traits,genotype,and phenotype.