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What is the cell theory and what does it state? What are the three major parts of the cell? What are three parts that all cells have? What parts of cells contain DNA? What is a good way to remember the different parts of a cell? Why are cells sometimes compared to a car or other mechanized structure? What are the four major classes of macromolecules? What is protoplasm in biology? What is cytology? What is the study of cells called? Why are cells important to biology?
What is cell biology? There are two different forms of cell division- mitosis and meiosis. Why do we need two forms? Do all cells use both forms? Why do you think that this is true? What are the advantages and disadvantages of each form of cell division? That means that approximately red blood cells could fit on the head of a pin. The optics of the lenses of a light microscope changes the orientation of the image.
A specimen that is right-side up and facing right on the microscope slide will appear upside-down and facing left when viewed through a microscope, and vice versa.
Similarly, if the slide is moved left while looking through the microscope, it will appear to move right, and if moved down, it will seem to move up. This occurs because microscopes use two sets of lenses to magnify the image. Due to the manner in which light travels through the lenses, this system of lenses produces an inverted image binoculars and a dissecting microscope work in a similar manner, but include an additional magnification system that makes the final image appear to be upright.
Most student microscopes are classified as light microscopes Figure 3. Visible light both passes through and is bent by the lens system to enable the user to see the specimen. Light microscopes are advantageous for viewing living organisms, but since individual cells are generally transparent, their components are not distinguishable unless they are colored with special stains.
Staining, however, usually kills the cells. Light microscopes commonly used in the undergraduate college laboratory magnify up to approximately times.
Two parameters that are important in microscopy are magnification and resolving power. Magnification is the degree of enlargement of an object. Resolving power is the ability of a microscope to allow the eye to distinguish two adjacent structures as separate; the higher the resolution, the closer those two objects can be, and the better the clarity and detail of the image. When oil immersion lenses are used, magnification is usually increased to 1, times for the study of smaller cells, like most prokaryotic cells.
Because light entering a specimen from below is focused onto the eye of an observer, the specimen can be viewed using light microscopy. The Xenopus egg nucleus alone is bigger than most of the cells found in humans. If the average human cell is the size of an average American house, frog eggs are the size of the Empire State Building!
Feric and Brangwynne want to know more about the mechanics of these skyscraper-sized cells. Giant Xenopus egg cells manage to support thousands of membrane-less compartments inside the nucleus. One type of these membrane-less compartments are the nuclear bodies. They are liquid-like drops, made up of RNA and proteins. Inside the nucleus, they act like droplets of vinegar in oil, that is, whenever they get close together, they fuse and sink.
Feric and Brangwynne previously found that an actin mesh was preventing the nuclear bodies from clumping by keeping them small.
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