Experiment BIO Microscopy AND THE Cells (2021 06 11 06 19 55 UTC) PDF

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Title MICROSCOPY AND THE CELLS Objectives 1. To describe the parts and functions of the compound light and dissecting microscope. 2. To state the steps in proper order for bringing the cell’s image into focus with the compound light microscope. 3. To calculate the diameter of the field and the total magnification of the Cell’s image. 4. To identify the differences between prokaryotic and eukaryotic cells. 5. To identify the differences between animal and plant cells. Introduction Microscopes are one of the most important tools used in a lab to observe minuscule forms of life in greater detail." Micro" refers to tiny, "scope" refers to view or look at. Microscopes are tools used to enlarge images of small objects so as they can be studied. The compound light microscope is an instrument containing two lenses, which magnify, and a variety of knobs to resolve (focus) the image. Because it uses more than one lens, it is sometimes called the compound microscope in addition to being referred to as being a light microscope. Microscopes work by magnifying objects and creating an image that is visible to the naked eye. The quality of the microscope is not determined by its ability to magnify objects, but by its ability to resolve objects, to distinguish detail. Light microscopes use visible light and an arrangement of lenses to magnify and resolve objects. Additionally, microscopy allows scientists to see transparent and translucent objects through the use of various staining techniques to enhance contrast in the image. Cells are the basic units of life. All organisms are made up of one or more cells. All cells emerge from pre-existing cells. This is known as "cell theory" There are two types of cells: prokaryotic and eukaryotic cells. Prokaryotic cells are the simpler cells with simple circular DNA and some basic organelles, and no nuclear envelope and no chromosomal proteins. For example, bacteria and blue-green algae. Eukaryotic cells (en= true, eukaryote nucleus) have a nuclear envelope. contain chromosomal proteins and various complex organelles. For example, single-celled protists, plant and animal cells.

In a compound light microscope, the specimen is illuminated by visible light, which is then passed through a glass lens. Magnification, resolution, and contrast are the three most significant parameters in microscopy. Magnifications are the ratio of an object’s image size to its real size. The following formula can be used to measure the total magnification: 𝑡𝑜𝑡𝑎𝑙 𝑚𝑎𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛 = 𝑜𝑐𝑢𝑙𝑎𝑟 𝑙𝑒𝑛𝑠 • 𝑚𝑎𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑜𝑏𝑗𝑒𝑐𝑡𝑖𝑣𝑒𝑠 𝑙𝑒𝑛𝑠 ▸Where the ocular lens is 10x

Materials Light microscope,slide,distilled water,animal cells,plant cells,coverslip,methylene blue,toothpick.

Procedure 1. 2. 3. 4. 5. 6. 7.

Onions are cut vertically and one layer of onion scales is removed. Next, the inner layer of the epidermis is extracted from the onion scales with forceps. A layer of the epidermis is placed on a glass slide that has water droplets on it. With the help of a needle, the specimen is closed with a glass cover. A drop of iodine is dropped on the slide. Filter paper is used to absorb excess iodine solution. Before using the microscope, clean the microscope level and lense using a clean white tissue. 8. Onion cells were observed using a microscope with a low force lens of 10x followed by a high force lens of 40x and 100x. 9. Repeat this step for the next specimen....