Cell theroy Flashcards
What are Cell theory ?
All living things are composed of cells .They maybe unicelluar or multi cellular .
In 1665 what did Robert Hooke Discover ?
He described cells and they defined them as “Cellule” based on pores in Cork(Cells)
Dead cell walls of plant cells
They appeared like small compartments when viewed in microscope .
He observed them in thin slices .
1665 , he published Micrographia , in which he describes and draws a lot of his observations.
Gave 60 observations under a compound microscope.
What did Anton van Leeuwenhoek discover ?
Living cells (bacteria and Protista ) He discovered protozoa .
1674 green algae 1676 Large bacteria 1677 Spermatozoa 1683 Dental Bacteria Ciliate Protista 1902
He was able to observe living organisms cells .Sperm being an example .
Saw animal cules included protozoa and other unicellur organism.
He called them little animalcules
What did Zacharias Janssen discover in 1590 ?
Invented the microscope
His father hans, also played a crucial role in the creation of the instruments.
What did Robert Brown observe in 1831 ?
He observed nucleus
discovering the nucleus of a cell
discovered the nucleus in plant cells
What did Theodor Schwan discover ? 1839
Credited universal theory
Animal Life is celluar
Yeast cells divide
Based on Modern cell theory
Concluded in 1839 that all tissues are made of cells and he wored on fermentation and discovered enzymes as pepsin
What did Rudolph Virchow discover ? in 1852
Evidence for the origin of new cells Rudolf Virchow published his findings to show new cells from existing ones
Omnis Cellule Cellua
Each cell arises from another cell
What did Louis Pasteur discover ?
Showed that bacteria growed in sterile nutrients broth after being exposed to air disapproving the theory of spontaneous generation of cells.
Disproving spontaneous generation .
He was the first scientists to prove that cells can only form pre existing cells .
What did Henri Durocher discover ? in 1824
Cellular Plant and animal life
Cell dissociation
Boiling nitric acid
Claimed cells were a physiological unit rather than a structural unit
He also discovered osmosis , which a passage of liquid through a semi permeable membrane investigated respirations , embrydoy and the effects of lights on plants .
What did Mathias Jacob Scheiden discover ?1838
recognized the importance of the cell nucleus.
Different parts of the cell parts of the plant organism are composed of cells or derivatives of cells.
Specifically, he observed that “the lower plants all consist of one cell, while the higher ones are composed of (many) individual cells.
proposes that all plant tissues are composed of cells, and that cells are the basic building blocks of all plants. This statement was the first generalized statement about cells.
Based on Modern Cell theory .
All living things life is composed of one or more cells.
Cell is a basic unit of life.
Satates that plant tissues are made of cells.
What did Robert Remak believe ?
All cells come from other forms of cells .
What are the three essential statements on Cell theory ?
- All living things are composed of one or more cells.
- The cell is the basic unit of life.
- New cells arise from pre-existing cells
Who were the three scientist directly develop the cell theory ?
Theodor Schwaan
Mathias Jacob Schiedam
While Rudolf Virchow contributed but not credited
What are three principles of Cells theory ?
All living organism are composed of one or more cells
Cell is the basic unit of structure and organisation in organism .
Cells arise from pre existing ones .
What is Light Microscope ?
Visible light is passed through the specimen and then through glass lenses .These lenses refract the light that the image of the specimen is magnified and projected in the eye .
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Cheap to purchase and operate
Small and portable
Natural colour of the specimen can be observed
Living as well as dead material can be viewed
Preparation is relatively quick and simple, requiring little expertise
Unaffected by magnetic fields
Magnifies objects up to 1500x
Preparation may distort specimen
The depth of the field is restricted
Has a resolving power for biological specimens of around 1nm.
