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प्रश्न
What is cell theory? Name the three scientists whose work led to the formulation of the cell theory.
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उत्तर
Cell theory was given by Schleiden and Schwann in the year 1838-1839. It was refined further by Rudolf Virchow.
The main postulates of cell theory are:
- All living beings are made up of one or more cells.
- Cells are the basic structural and functional unit of all living beings.
- All cells are basically alike in chemical composition and metabolic processes.
- New cells arise by the division of pre-existing cells. (Rudolf Virchow)
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संबंधित प्रश्न
Who discovered cells and how?
Carry out the following osmosis experiment:
Take four peeled potato halves and scoop each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
- Keep cup A empty
- Put one teaspoon of sugar in cup B
- Put one teaspoon salt in cup C
- Put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then, observe the four potato cups and answer the following:
- Explain why water gathers in the hollowed portion of B and C.
- Why is potato A necessary for this experiment?
- Explain why water does not gather in the hollowed-out portions of A and D.
Which part of the cell contains organelles?
Differences between light microscope and electron microscope.
Which one of the following is found both in the cells of a mango plant and a monkey?
Define the term cell? Also, describe types of cells.
What was the contribution of the following to our knowledge of cells?
Robert Hooke
Where is energy stored in a cell?
When will you use a simple microscope and when, a compound microscope? Explain in detail how you will use them.
Answer the following question.
Why is the cell called the structural and functional unit of life?
