Cell Structure

Objectives:
1. Prepare specimens for staining.
2. Identify unique and standard structures of the microscopic world. 3. Identify and use different stains for the different types of organelles. Results:
a) Epidermal cells of plants:

Upper surface or Rheo discolours leaf
Low power: 40X

Upper surface or Rheo discolours leaf
Low power: 40X

Upper surface or Rheo discolours leaf
High power: 100X

Upper surface or Rheo discolours leaf
High power: 100X

Explanation:
Shapes of the cell| |
Arrangement of the cell| |
Details of the cell structures|
Organelles| Functions|
Stroma| |
Epidermal cell| |

Questions:
1. Do the cells different with and without eosin in any particular respect? If so what differences do you observe? | Epidermal cell with eosin| Epidermal cell without eosin| | | |
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Lower side of the Rheo leaves
100X
Lower side of the Rheo leaves
100X

Explanation:

Questions:
1. Has the lower epidermis the same structure as the upper epidermis? | Upper epidermis| Lower epidermis|
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2. Do you find any cells which contain green plastid? What is the shape for such cells? Green plastid:
* Shape:
* Function:
3. Comparison peels from leaves of Zebrina and corn.
| Zebrina| Corn|
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b) Cell Wall and Middle Lamella
Middle Lamella
Middle Lamella

Explanation:
Structure| Description| Function|
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c) Yeast Cells (Saccharomyces)

Yeast Cell
100X
Yeast Cell
100X

Explanation:

Questions:
1. On a slide mount a drop of yeast in lactophenol. What can be seen under high power? Structure| Description| Function|
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2. How does the stain help to make out details of the cells?

3. Yeast reproduces by budding: one or more buds grow out from the parent cell and eventually break away. Can you see yeast cells budding? What is the significance of budding?

4. In what way does the yeast cell resemble: a) an animal cell ? b) a plant cell? What conclusion do you draw from the comparison? Animal| Plant|
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d) Blood Cells
Blood Smear
1000X
Blood Smear
1000X

Explanation:
Structure| Description| Function|
Red blood cell| | |
Basophil| | |
Eosinophil| | |
Neutrophil| | |
Lymphocyte| | |

Questions:
1. Granulocytes move by amoeboid locomotion and engulf bacteria by phagocytosis. What other unusual feature is apparent in these cells? | Red blood cell| White blood cell|
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2. While looking at the blood smear notice the red blood cell. How do they differ from typical animal cells? | Blood smear| Animal cell|
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e) Spirogyra Cells
Spirogyra cells
400X
Spirogyra cells
400X

Explanation:
Structures| Functions|
Spiral chloroplast | |
Nucleus| |
Cell wall| |
Cytoplasmic bridles| |
Pyrenoid| |

Questions:
1. Can you identify the cell wall? Study the shape of the chloroplast with the pyrenoids, cytoplasm, nucleus suspended in the centre of vacuoles by cytoplasmic bridles. What is the 3-dimensional shape of the cells?

2. Investigate the detailed structure of the cells by staining 3 separate slides with
a) acetocarmine for the nucleus
b) methylene blue for cell wall
c) iodine solution for starch grains near the pyrenoids
Structures| Description|
Nucleus| |
Cell wall| |
Pyrenoid| |

3. The cell wall contains mucilage (slimy). Why is this useful?

f) Flagellum

Euglena
400X
Euglena
400X