Mendel published his work on inheritance of characters in 1865, but it remained unrecognized till 1900

Mendel published his work on inheritance of characters in 1865, but it remained unrecognized till 1900. Give three reasons for the delay in accepting his work.

The communication was not easy in those days and his work could not be widely publicised.
His concept of genes as stable and discrete units that controlled the expression of traits and of the pair of alleles which did not blend with each other was not accepted by contempraries as an explanation for the apparently continuous variation seen in nature.
Mendel’s approach of using mathematics to explain biological phenomena was totally new and unacceptable to many of the biologists of his time.
Though Mendel’s work suggested that factors were discrete units, he could not provide any physical proof for the existence of factors and what they were made of.