CELLS-a historical perspective

first microscopes invented

• Robert Hooke viewed thin slices of cork from a tree and saw small box-like compartments that he called 'cells'
• Credited as the first person who discovered cells.
• However, wasn't looking at living cells but remnants of dead and empty plant cells.
• First to realise that this platn material had organised structure at microscopic level

• Dutch Anton van Leeuwenhoek use simple microscopes to observe material that he scraped form between his teeth.
• Saw first bacterial cells.
• Inspired by Hooke's MICROGrAPHIA

• Robert Brown involved in dispute about how pollination and fertilisation occured in plants.
• Noted the nucleus and named it.
• First to introduce concept of nucleated cell as the unit of structure in plants.

• Matthias Schleiden suggested cells were basic structural unit of all plant matter
• Theodor Schwann proposed animals were aggregates of cells arranged according to a definate law.
• Shared ideas over dinner and came to recognise that both plant and animal tissues have a cellular organisation.

• Basic idea arising from work of schwann and schleiden published -known as the CELL THEORY:
• "all living thinsg consist of one more more organised structures that are called cells or of products of cells"
• "cells are the basic funcitonal unit of life"

• Rudolf Virchow challenged the idea of spontaneous generation (the idea that living things could arise from dead matter or inanimate objects) with his concept of BIOGENESIS (from bio=life, genesis = origin/creation).
• Proposed that new cells come form existing cells.
• Virchow's contribution extended CELL THEORY to include the basic concept " new cells are produced from existing cells"

Louis Pasteur carried our experiments that conclusively disproved spontaneous generation and supported the view that new cels are produced by existing cells.

electronic microscope invented