Cell theory

The emergence and further development of microscopy led to the creation of a cell theory, created in 1839 by two German researchers M. Schleiden and T. Schwann.

Stages of creating a cell theory

• 1590 – Creation of the first microscope (Jansen brothers).
• 1665 Robert Hooke – introduced the name “cage”.
• 1696 – Anthony Levenguk’s publication on microbes and other microscopic objects seen through a microscope.
• 1831 – R. Brown described the nucleus of a plant cell.
• 1839 – M. Schleiden and T. Schwann opened the nucleolus and put forward the main provisions of the cell theory.

In the future, the cell theory developed thanks to new discoveries.

• 1859 – Rudolf Virchow’s principle: “every cell is from a cell” (M. Schleiden and T. Schwann mistakenly believed that cells in the body arise from non-cellular matter).
• 1880 – Walter Flemming described chromosomes and the processes that occur during cell division (mitosis).
• 1892 – I. I. Mechnikov discovered the phenomenon of phagocytosis.

The 20th century became the century of the flourishing of biology, especially of such sciences as cytology, genetics, embryology, biochemistry, and biophysics. Without the creation of a cell theory, this development would have been impossible.

• Since 1903, genetics began to develop.
• Since 1930, electron microscopy began to develop actively, which allowed scientists to study in detail the cellular organelles.

The main provisions of modern cell theory:

• all simple and complex organisms consist of cells capable of exchanging substances, energy, and biological information with the environment.
• A cell is an elementary structural, functional and genetic unit of living things.
• A cell is an elementary unit of reproduction and development of living things.
• In multicellular organisms, cells are differentiated in structure and function. They are combined into tissues, organs, and organ systems.
• The cell is an elementary, open living system capable of self-regulation, self-renewal and reproduction.

The similarity in the structure of cells of various organisms, the commonality of their basic properties confirm the commonality of their origin and allow us to draw a conclusion about the unity of the organic world.