protoplasm

What is the physical basis of life? 

In 1868, T. H. Huxley described protoplasm as the “physical basis of life”. Protoplasm is a clear, colourless and jelly-like substance which seemed to make up the contents of the cell. It was also described as “substance of life” or “living material”.

Who discovered it?

In 1835, Felix Dujardin was the first person to observe the living substance and called it “sarcode”. But in 1940, J. E. Purkinje gave it a name i.e. “protoplasm – the first substance”.

What is protoplasm theory & who gave it?

Protoplasm theory was given by O. Hertwig in 1942. This theory states that:

  • Protoplasm is the only living material which has the vital forces necessary for life.
  • All organisms are composed of protoplasm.
  • Protoplasm is similar in all organisms.

What is the physical nature of protoplasm?

Protoplasm is a translucent, colourless, jelly-like gelatinous substance. It is slimy to touch and slightly heavier than water and coagulates on heating. It can be stretched like a thread which returns to its original position when released.

The most important physical characteristic of protoplasm is its colloidal nature to which it owes most of its properties. Protoplasm is a complex mixture of two types of aqueous solution.

  1. A colloidal solution of organic compounds (proteins, fats, starches).
  2. A molecule solution of both inorganic & organic substances (salts & sugars).

What is the present view on Protoplasm?

The term “protoplasm” has lost its original significance of being a special substance with the qualities of life. Today, protoplasm is simply a collective term for the components of the living part of a cell. It does not have an independent identity.


 References:

Books:

  • Karp, Gerald. Cell And Molecular Biology. Hoboken, NJ: John Wiley, 2010. Print.
  • NCERT, Biology: Textbook for Class XI. New Delhi: NCERT, 2006. Print.

Websites:

  • “protoplasm”. Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2016. Web. 11 Mar. 2016.
  • “Protoplasm”. Botany.uwc.ac.za. N.p., 2016. Web. 11 Mar. 2016.

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