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प्रश्न
What is the cell theory? Who propounded it and when?
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उत्तर
All animals and plants are composed of cells, which serve as the units of structure and function. This, in short, is called the Cell Theory,
Cell theory was propounded by Theodor Schwann and Matthias Schleiden in the year 1839 and was modified by Rudolf Virchow in 1858.
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संबंधित प्रश्न
Where are chromosomes found in a cell? State their function.
Do you think the cells of an elephant would be larger than the cells of a rat? Explain briefly.
Match the name of the organelle given in Column A with its function given in Column B.
| Column A (Organelle) | Column B (Function) | ||
| 1 | leucoplast | a | help in cell division |
| 2 | nucleus | b | transport of material |
| 3 | ribosomes | c | making food |
| 4 | mitochondria | d | digesting foreign bodies |
| 5 | endoplasmic reticulum | e | storage of starch and proteins |
| 6 | golgi bodies | f | making the cell turgid |
| 7 | chloroplast | g | making proteins |
| 8 | centrosome | h | controlling all the vital activities of a cell |
| 9 | vacuole | i | releasing energy |
| 10 | lysosomes | j | synthesis of cell wall in a plant cell |
Who proposed the Cell theory? Explain the main points of this theory.
Define the term cell? Also, describe types of cells.
Name any five cell organelles.
What was the contribution of the following to our knowledge of cells?
Schwann
Describe the structure of the chromosome in brief.
Match the items in column A with the appropriate items in column B:
| column A | column B |
| 1. Platform or workplace for the synthesis of proteins | a. Golgi complex |
| 2. A powerhouse of cells | b. Ribosomes |
| 3. Help in the formation of cell plate during cell division | c. Chloroplast |
| 4. Site for photosynthesis | d. Mitochondria |
| 5. Control tower of cell | e. Chromosomes |
| 6. A structure bearing genes | f. Nucleus |
Sketch and describe in your own words, the animal cell
