BioLabreport2.pdf - ProkaryoticCellsvs.EukaryoticCells...

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Unformatted text preview: Prokaryotic Cells vs. Eukaryotic Cells Biology Lab Eliana Klein 22 September 2016 Introduction: The study of cells is called Cytology. It studies the structure and function of all different types of cells. Some common tools cytologists use are the light microscope, electronic microscope, and cell chemistry. A microscope is ​an optical instrument used for viewing very small objects, such as mineral samples or animal or plant cells, typically magnified several hundred times. A cell is defined by the fact that it is t​he smallest structural and functional unit of an organism, consisting of a cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic. ​To understand the differences between prokaryotes and eukaryotes cells we can identify structural characteristic of each cell. The first thing to note in the cells differences is their structure. The largest difference is that Eukaryotic cells have organelles. Organelles are membrane­bound compartments within a cell, such as the nucleus, mitochondria, chloroplasts, Golgi, and ​endoplasmic reticulum​. Eukaryotic cells contain membrane­bound organelles, including a nucleus. Prokaryotic cells do not contain a nucleus or any other membrane­bound organelle. Prokaryotes include two groups: bacteria and archaea. We focus on the bacteria in this lab as well as plant and animal cells. The objective of this lab is to differentiate and compare Prokaryotic cells and Eukaryotic cells and their structures through viewing them under a microscope. The hypothesis is that we will be able to see a nucleus in the Eukaryotic cells and not the Prokaryotic cells. The results showed that B­D were Prokaryotic cells and E­I were Eukaryotic cells. Materials: 1. Microscope 2. Glass slides 3. Coverslip 4. “e” slide 5. Oscillatoria (cyanobacteria) 6. Gloeocapsa (cyanobacteria) 7. Yogurt (​Lactobacillus acidophilus, bacteria) 8. Elodea (plant cell) 9. Onion (​Allium cepa, plant cell) 10. Human epithelial cell (animal cell, from inside cheek) 11. Spirogyra slide (plant cell) 12. Blue, red, and green dye 13. Q­tip swabber 14. Pipette dropper 15. Tweezers 16. Ruler Procedures: A. Examination of “e” slide 1. The microscope was removed from the cabinet and carries in an upright position with one hand grasping the arm and the other supporting the base and then placed on the lab counter. The microscope was plugged in and turned on. 2. The nosepiece was rotated to (4X) objective and aligned with the light source. 3. The slide was placed under the microscope on the horizontal stage, directly below the scanning objective lens. 4. The slide was viewed through the oculars with both eyes. 5. The coarse adjustment knob was located on the side of the microscope and adjusted as needed until the field of view was made clear and the image was able to be seen clearly. The focus was adjusted to get the clearest image possible. 6. The image can then be viewed in (4X), (10X), & (40X). 7. The “e” slide was examined under (4X), (10X), & (40X). 8. The field of view was measured in mm with a ruler to find the area under (4X). The diameter was 4mm and the radius was 2 mm. Using the formula for area: Area = ​π x r^2. The results were 12.56mm^2. 9. All results were recorded in a personal notebook. B. Examination of Oscillatoria 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a small droplet of water from a culture labeled “Oscillatoria” on a clean glass slide. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. 2. Repeat steps 2­6 from ​A​. 3. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. C. Examination of Gloeocapsa 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a small droplet of water from a culture labeled “Gloeocapsa” on a clean glass slide. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. 2. Repeat steps 2­6 from ​A​. 3. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. D. Examination of Yogurt bacteria 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a small droplet of water and a small droplet of yogurt on a clean glass slide. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. 2. Repeat steps 2­6 from ​A​. 3. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. E. Examination of Elodea (plant cell) 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a small droplet of water and a torn off piece of leaf from the tip of the Elodea plant and place on a clean glass slide. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. 2. Repeat steps 2­6 from ​A​. 3. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. F. Examination of Onion Cell (red dye) 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a thin piece of onion from the inner epidermis on a clean glass slide. 2. We then stainer the onion by placing a small droplet of red dye on the onion. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. The tissue sat for 5 minutes to allow the dye to fully set in. 3. Repeat steps 2­6 from ​A​. 4. The nucleus was visible in the central part of the cell. 5. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. G. Examination of Onion Cell (green dye) 1. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing a thin piece of onion from the inner epidermis on a clean glass slide. 2. We then stainer the onion by placing a small droplet of green dye on the onion. Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. The tissue sat for 5 minutes to allow the dye to fully set in. 3. Repeat steps 2­6 from ​A​. 4. The mitochondria was visible on the slide. 5. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. H. Examination of Epithelial Cell (inner cheek swab, animal cell) 1. Using the ​Q­tip, we swabbed our inner cheeks. 2. The slide was not previously prepared so we prepared a wet mount for the specimen being evaluated. A wet mount was made by placing t​he scrapings from the Q­tip on a clean glass slide. The tissue was then dyed by placing a small droplet of blue dye on the slide. ​ Then a coverslip was slowly placed over the slide to avoid air bubbles from forming. The tissue sat for 5 minutes to allow the dye to fully set in. 3. Repeat steps 2­6 from ​A​. 4. The nucleus was visible in the central part of the cell. 5. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. I. Examination of ​Spirogyra slide (plant cell) 1. A slide had been previously prepared so we did not need to prepare a wet mount. 2. Repeat steps 2­6 from ​A​. 3. The cellular structures were observed and our field of view at (40X) was drawn in our personal notebook. Results (cell drawings): B. C. D. E. F. G. H. I. Discussion: The results show that in each of the Eukaryotic (E­I) cells a nucleus was visible. The nucleus appeared as a small dot in or around the center of the cell and was darker than the rest of the cell, this is shown in the images above. A nucleus was non existent in the Prokaryotic cells (B­D). The cell walls are visible in each of these cells, but it is clear that there is no nucleus. The hypothesis was proven to be true. We were able to see the nucleus in eukaryotic cells and were not able to see a nucleus in the prokaryotic cells. The bacteria is much smaller than the plant and animal cells and isn’t enlarged enough to see the full structure of the cell.The results of each cell were shown in the drawings above. A possible source of error would be that I hadn’t properly created a wet mount therefor resulting in an nonvisible cell. Another possible error would be that the cell wasn't properly dyed, also resulting in an nonvisible cell. The results relate to my existing knowledge about the structure of cells. I was able to see first hand the structural difference between a Eukaryotic and a Prokaryotic cells with my own eye. ...
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