Evidences from cytology and genetics

Prokaryotic and eukaryotic cells show definite relationship.

Among eukaryotes, the plasma membrane and organelle diversification in plant and animal cells has definite correlation.

The procees of protoplast and cell fusion / hybridization is based upon same principle.

Cellular processes and patterns of division are same.

Principles and laws of heredity apply to all organisms in same way except some individual differences.