How did scientists discover the common structure of cells?

They used the mcroscope to observe the structures of the cell. Some scientists draw while they are observing in the microscope

The question says,' in which of the following stages is mitosis most important. The correct option is C, that is,' a cub tiger begins to grow'. Mitosis is a type of cell division that takes place throughout one's life. It is required for growth and development. Mitosis ensure growth and repair of damage tissues in multicellular organisms.