Mixing carbon and iron to make steel is a physical change or chemical change
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<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2><h2>_____________________________________</h2>
the Cell Theory was give by German scientists, Schleiden and T.Shwan in 1839. It stated that,
- All organism are composed of one or more cells
- The cell is the structural and functional unit of life
- It is a de novo structure, that means it COULD arise from non living thing which was incorrect.
It was corrected by the German pathologist Rudolf Virchow in 1855. He made a convincing case, corrected and added the third point of the cell theory. It is,
- Cells can arise only by a division of pre-existing cell. It is <u>NOT</u> a de novo structure.
Cell theory brought a great evolution in the field of biology which established the function of organism is the result of activities and interaction of the cell units.
<h2>_____________________________________</h2>- <u>Flask 1</u>: It is observed that there are no micro-organism, this is because the meat is sealed and no micro-organism could enter through it.
- <u>Flask 2</u>: It is observed that there are micro-organism present because meat is not sealed but open.
- <u>Flask 3</u>: As the S tube is used, the micro-organism are not able to reach the meat because of the curvy path
These observations support the point that<u> cells could arise only by a division of pre-existing alive cells</u> because in Flask 1 when there were no micro-organism present so there was no organisms found so no micro-organism arised, In flask 3 the S tube was used so no micro-organism could reach the meat thus there were no organism there which could divide to reproduce. The flask 2 was open, so the micro organisms reached the meat so they divided which means Cells can only arise by a division of pre-existing cells.
<h2><u>_____________________________________</u></h2><h2>Best Regards,</h2><h2>'Borz'</h2>