Cell Theory

The discovery of cell was possible solely because of the invention of microscope. Inspired by Hook’s Micrographia – Antonie van Leeuwenhoek, a Dutch shopkeeper and a lens crafter, learned to grind lenses and made his own simple microscopes with a magnification of more than 250x. With the help of these microscopes, in the 1670s, he discovered living single celled organism – bacterial and sperm cells, to which Leeuwenhoek collectively called as animalcules meaning “little animals”. Robert Hooke, an English scientist was the first to observe the microscopic boxlike structure – “Cells”, while studying the thin slices of cork. In a 1665 publication called Micrographia, it was Hooke who coined the term “Cells”. The boxlike cells of cork reminded him of the individual rooms in a monastery, which were known as cells.
Cell theory is one of the basic tenets in the field of biology. Around hundred or more years later, in 1824, Henri Milne-Edwards, an eminent French zoologist proposed that the basic structure of all animal tissues was an array of “globules”. Henri Dutrochet (1776–1847) proposed that the cells are both structural and physiological unit for plants and animals. In the late 1830’s, the idea of cell theory was proposed by botanist Matthias Schleiden and zoologist Theodor Schwann while studying tissue.

However, in 1858, Rudolph Virchow, a German biologist, pathologist and physiologist later contributed to the cell theory by stating – “Omnis cellula e cellula”, which means “All cells develop from the pre-existing cell”. Even though the theory did not unveil the concept of cell origin or from, where did the first cell come from. The theory is widely accepted by scientific community.

The Cell Theory states:

a) The cell is the fundamental basic unit of all organisms.

b) All organisms are composed of one or more cells.

c) All cells develop from the pre-existing cell during cell division.

The extended or present day version of cell theory also includes:

a) Genetic material inside the cells are passed on to the daughter cells during cell division.

b) All cells possess the same chemical composition.

c) The biochemical energy flow occurs within cells.


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Questions:

Cell Theory

  1. Who coined the term “Cell”?
  2. What is the extended or the modern version of cell theory?
  3. Who proposed the idea of cell theory?
    a) Robert Hooke
    b) Matthias Schleiden and Theodor Schwann
    c) Antonie van Leeuwenhoek
    d) Rudolf Virchow
  4. Who stated “Omnis cellula e cellula”, which means “All cells develop from the pre-existing cell”?
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