Science 10 – Unit C - BIOLOGY Chapter 1 – The Microscope C1.3 & C1.4 - Development in imaging, staining, and cell research Factors affecting the quality of an image in microscopy: Magnification o improved with advancements in lens-making o light microscopes used in labs today can now magnify Contrast o refers to o it is contrast that allows the human eye to focus on different aspects of the image and o cells by themselves are mostly colourless o image quality has improved with: Resolution o the ability to o the human eye is capable of resolving objects that are o the higher the resolution of a microscope, o similar to the resolution capabilities of a digital camera Fluorescent microscopy fluorescent stains called GFP (green fluorescent protein) are introduced to the specimen different cell structures absorb stains in different amounts the specimen is subjected to UV light depending on the type of dye, the cell glows either unlike conventional staining, Types of microscopy: Brightfield microscopes o light o fixing and staining process kills the specimen o you can’t view o limited resoloution o you can’t get any higher resolution than Confocal technology o uses lasers and computers to focus the light o the later reflects off the object and back to the eyepiece o you see o computer software can be used to o fluorescent stains work better with confocal microscopes because Electron microscopy o uses a fine beam of electrons instead of light o the electrons pass through different materials at different rates, due to o instead of lenses, EMs use o Transmission Electron Microscope (TEM) electrons 100X better magnification and resolution than light microscope difficult to specimens are fixed and stained, so o Scanning Electron Microscope (SEM) good for observing the specimen is the electrons reflect off the gold and 2X better image quality than the TEM uses computes to new SEMs permit the use of Gene mapping o with new imaging techniques comes new possibilities for o gene mapping refers to o an organism’s genome refers to all the information contained o in 2001, the Human Genome Project published a o could help us understand where cancer and other diseases o also allows us to ethical arguments arise about the dangers of Cell communication o cells are open systems, meaning o hormones are chemicals produced in one part of your body for example, the hormone adrenaline is produced in your brain, but acts all over your body hormones and other transmitter chemicals form part of your cells’ communication system o receptors on the surface of the cells allow transmitters to attach to the cell and carry out their function only transmitters similar to a certain viruses and bacteria can trick the cells by in order for your immune system to fight off invaders, it must first o better understanding of cell communication allows scientists and research companies to: diagnose diseases diagnose diseases make Homework Page 264 #1, Page 265 #10, 11 Complete the following table: Feature Light microscope illumination focused by how image is viewed advantages disadvantages Electron microscope