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The Invention of the Microscope and the Discovery of Cell

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The Invention of the Microscope and the Discovery of Cell:

Cell Biology History - A Timeline

1665 Robert Hooke had successfully invented the microscope. Because of this discovery, Robert Hooke was the first one to have a close look of a cell that appears to be. While examining a thin slice of cork, Robert Hooke saw that the cork resembled the structure of a honeycomb consisting of many little compartments. Cork is a substance that comes from the bark of a tree. This was in the year 1665 when Hooke made this chance observation through a self-designed microscope. Robert Hooke called these boxes cells. Cell is a Latin word for ‘a little room’. However, the cell walls observed by Hooke gave no indication of the nucleus and other organelles found in most living cells.

 

Robert Hooke

1674

Leeuwenhoek (1674), with the improved microscope, discovered the free-living cells in pond water for the first time.

Antonie van Leeuwenhoek

1825 French scientist Francoise Raspail established one of the Concepts of cell theory: that all cells arise from pre-existing cells. The basis of this was the witnessing of binary fission under a microscope wherein a single cell divided into two daughter cells.

François-Vincent Raspail

1831

It was Robert Brown in 1831 who discovered the nucleus in the cell.

    Robert Brown

1839

Purkinje in 1839 coined the term ‘protoplasm’ for the fluid substance of the cell. 

Jan Evangelista Purkyně

Basic optical parts of a microscope include -

  • Eyepiece: The lens from which the viewer looks through to see the specimen. The eyepiece usually contains a 10X or 15X power lens.
  • Coarse adjustment: It brings the specimen into general focus.
  • Fine adjustment: It focuses and increases the detail of the specimen.
  • Illumination: It is the light source for a microscope. Older microscopes used mirrors to reflect light from an external source up through the bottom of the stage. Most microscopes now use a low-voltage bulb.
  • Condenser: Gathers and focuses light from the illuminator onto the specimen being viewed.

Example

Answer the following question.

Who discovered cells, and how?

Robert Hooke discovered the cells. He saw that the cork resembled the structure of a honeycomb consisting of many little compartments. Cork is a substance which comes from the bark of a tree. This was in the year 1665 when Hooke made this chance observation through a self-designed microscope. Robert Hooke called these boxes cells. In this way, he discovered the cells.

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