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Question
What is cell theory? Name the three scientists whose work led to the formulation of the cell theory.
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Solution
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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RELATED QUESTIONS
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.
Try to find the names of four cell organells hidden in this maze, (hint: The hidden words can appear horizontally or vertically; forwards or backward or even mixed up). Write them in the lines provided. For example : “NUCLEUS” in the last row, seven backward letters.
| A | J | F | B | H | E | M | O | E | L | O | U | C | A | V |
| H | V | L | E | U | C | O | P | L | A | S | T | N | O | E |
| C | H | R | O | M | O | P | L | A | S | T | X | T | E | R |
| S | U | E | L | C | U | N | W | P | L | A | S | T | I | D |
Write a short answer.
Why is a cell called the structural unit of a living organism?
What is the function of the following?
Ribosomes
What is the function of the following?
Cell membrane
Expand - ER
Who studied the cell first?
Which is the longest human cell?
When will you use a simple microscope and when, a compound microscope? Explain in detail how you will use them.
I take part in food production of a cell. Who am I? ____
