Father of Cytology – Robert Hook Rudolf Virchow proposed – Theory of cell lineage, Omnis cellula–e cellulae (all cells living cells are arises from pre-existing cells) The cell is the structural, functional, and fundamental unit of an organism. Cell theory – A cell is a basic unit of life that arises from pre-existing cells. · Viruses are the exception to the cell theory. Cellular totipotency · Cellular totipotency given by Haberlandts and Experimentally proved by Stewart et all. · Ability of a vegetative cell to grow into a new plant. Types of Cell A. Prokaryotic cell: (Pro – Primitive, Karyon: nucleus) · True nucleus is absent. · Nucleus is an incipient type called Nucleoid. i.e, that lacks Nuclear membrane, Nuceloplasm and Nucleolus. Note : Chondroid – primitive mitochondria, Viroid – primitive virus. (Viroids are the smallest infectious agent made up of nucleic acid only) · DNA is single circular, double-stranded, non-repe...