The cell is the fundamental building blocks of all living things. It is the structural and functional unit of all living organisms. To obtain a detailed image of cells, microscope is necessary. The cell theory was first developed by Matthias Jakob Schleiden and Theodor Schwann in 1839. Important functions of an organism occur within the cells and all cells have hereditary information essential for regulating cell functions and for sending out information to the next generation of cells.
Robert Hooke was responsible in naming the cell and he discovered the cells in cork and in plant tissue using an early compound microscope. To give you an overview, microscope is instrument for viewing small objects that cannot be seen through the naked eye and the science of investigation is called microscopy. Microscopic objects are very small objects that need to examine under a microscope in order to be seen. Microscopes come in different types and it varies according to their specifications. Hookes study of the cell with the aid of microscope is interesting and informative which gives science a great leap.
The cork is a perfect specimen for your microscopy study of the cells and tissues. To make the preparation, get hold of a bottle cork. Slice off the thinnest possible sliver from the rounded side of the cork using a sharp, single edged razor blade. Mount the cork shaving on a microscope glass slide in a drop of water and cover with cover glass. Look for cells on a cut edge of the cork piece. It is here that a layer of cork only one or two cells thick is likely to be found.
Cells of animals do not have cell walls. Make a stained mount of cells on a microscope glass slide obtained from an animal to be in agreement. A microscopist can also supply himself the cells needed. Just take the blunt end of the toothpick and gently scrape the inside of the cheek in the area opposite the back molars. Smear the material on the end of the toothpick over the center of a clean microscope glass slide. Cover the smear using few drops of dilute methylene blue stain. Place a microscope cover slip and examine under a high and a low powered microscope.
The cheek lining cells are epithelial cells of the type that line or cover most of the body structures. Cells here are thin and flat, and are well adapted to covering surfaces. Many cells appear wrinkled and folded over on themselves when viewed underneath a microscope. It is possible to observe the granular nature of the cytoplasm, the semi liquid cellular content within the cell membrane when the nuclei are stained darkly.
Slicing a bit of meat from a steak before it is put under a broiler easily demonstrates muscle cells. Place a diminutive shred of meat on a microscope glass slide, add a drop of water and tease the tissue apart with a pair of dissecting needles. Then cover with a cover slip when it has been reduced to the smallest possible fiber size, and examine under a microscope. To improve the visual appearance of nuclei and the striped structures of this kind of muscle tissue, the microscopist cal stain the fibers. Plant tissues are as interesting as those of the animals. A plant, for example, is often compared to a complicated factory where starches and sugars are manufactured from non-living raw materials. There also are the openings in the leaf that control the passage of materials in and out of the factory. These openings are called stomates, a word which also means a mouth.
Obtain a leaf from a plant that has fleshy, succulent tissues to demonstrate the stomates. Best samples are Sempervivumde, Sedum or stonecrop, Tradescantia, Peperomia, or head lettuce. To curl the leaf, taut with the forefinger, then using a sharp knife or single edged razor blade, cut part way through the underside of the leaf. Be careful not to cut your finger in the process. Peel away a very thin, transparent layer of the lower epidermis, starting at the slit. The layer peeled away should be no more than one cell layer thick. Mount the tissue flat on the microscope glass slide, add a drop or two of water, then, cover and examine under a microscope. Focus on the network of irregularly shaped epidermal cells and the occasional paired crescents of the guard cells that surround the stomates in the leaf. The guard cells can open or close the stomates to regulate the passage of substances in and out of the leaf.
An active and dynamic substance made material is within the membrane of a living cell. The movement of the cytoplasm within the ell is called cyclosis and may also be seen in cells of a leaf of a common aquarium plant called Elodea. Detach a leaf from the tip of the most active growing part of the plant and mount it right side up in a drop of warm water on a microscope glass slide. Lower a cover slip into place and focus on the upper layer of the cells along the midrib of the leaf both under a low powered and a high powered microscope. The chlorophyll in this leaf is distributed throughout the cytoplasm called chloroplasts. Observe the movement of the cells.
The movement of the chloroplasts is due to the streaming flow of the cytoplasm within the membrane of the cell. Suspended in the cytoplasm, the chloroplasts are swept along on their journey around the cell as the cytoplasm moves. By exposing the plant to the warming light of an electric lamp for about an hour before preparing the specimen for observation under the microscope, the rate of the cyclosis may be increased.
