| What is magnification? | How much bigger the image than the actual specimen |
| What is resolution? | Ability to distinguish between two point |
| What is a microscope? | An instrument used to study very small objects with our naked eyes. |
| What is a light microscope? | Device that uses visible light and a series of lenses to produce an enlarged image of an object. |
| What are the advantages of the light microscope? | It is cheap, portable and live |
| What are the disadvantages of a light microscope? | Low magnification, low resolution |
| What is an electron microscope? | Device that uses electrons and a beam of them to produce an enlarged image of an object. |
| What are the advantages of an electron microscope | More detailed, 2,000,000x magnification, TEM most detail 2D, SEM 3D, allows you to see internal structures in the cell like the ribosomes, the nucleus, and the chloroplasts in plants. |
| What are the disadvantages of electron microscope? | Very expensive, not portable, and have to have a thin coating of metal added before they are put in the vacuum chamber. |
| What is the equation for total magnification? | Total magnification = eyepiece lens x objective lens |
| How would you create an animal cell slide? | 1. Using a cotton bud, swab the inside of your cheek to extract cells
2. Rub the cotton bud onto the centre of the clean microscope slide
3. Add a drop of methylene blue stain
4. Using a mounted needle, slowly lower a coverslip over the stain
5. View under a microscope at low power and then increase the magnification. Add the total magnification |
| What size do animal cells range from? | 0.01mm - 0.05mm |
| How would you create a plant cell slide? | 1. Using tweezers, peel off a single onion layer of onion skin
2. Lay flat on top of a clean microscope slide
3. Add a drop of iodine
4. Using a mounted needle, slowly lower a coverslip over the stain
5. View under a microscope at low power and then increase the magnification. Add the total magnification |
| What size do plant cells range from? | 0.01mm - 0.10mm |
| How much magnification can an industrial microscope go up to? | x2000 |
| What is the job of the stage? | It is where you position your specimen under a microscope slide. It can be moved up and down. |
| What types of lens help us too magnify or enlarge an object in a light microscope? | Objective lens and eyepiece lens |
| What is the job of the light in a light microscope? | A light source that is built in to have a bulb inside already. Some times, you may have a mirror instead and you would have to place it on top of a deak near a window to reflect light. |
| What is the objective lens in a light microscope | A curved piece of glass that makes the specimen appear bigger. They vary in their magnifying strength usually around x10 -> x40 on a school light microscope. |
| What is the total magnification of a microscope if there is magnification of eyepiece lens of x10 and objective lens of x40? | Total magnification = eyepiece lens x objective lens
? = x10 x x40
? = x400 |
| What is the job of the eyepiece lens? | This is the lens at the top you look through with a magnification of x10. |
| What does the coarse focus do? | It moves the stage up and down |
| What does the fine focus do? | It is the more precise focus. |
| What is a coverslip? | A square of thin, transparent plastic or glass |
| What is iodine solution used for in light microscope for cells? | To highlight objects in a cell by adding colour to them |
| How would you set up a light microscope by preparing your slide? | 1. A dd a drop of water to the centre of a clean slide
2. Cut onion and separate it into layers out. Use tweezers to peel off some epidermal tissue from the bottom of one of the layers
3. Using tweezers, place the epidermal tissue into the water on the slide
4. Add a drop of iodine
5. Place a coverslip on top. |
| What is eosin for? | Used to make the cytoplasm show up |
| How would you set up and use the light microscrope? | 1. Clip the slide that been prepared onto the stage
2. Select the lowest-powered objective lens first. This gives the lowest magnification.
3. Use the coarse adjustment knob to move the stage just under the objective lens
4. Look through the eyepiece. Use the coarse adjustment knob until the stage downwards until the image is roughly in focus
5. Adjust the focus with the fine focus knob, until there is a clear image on the slide
6 Use the higher-powered objective lens and refocus to see a slide with greater magnification |
| Name a rule for using low power and high power drawings? | Use a sharp pencil to draw smooth lines |
| When drawing a cell, what should you use to measure real length? | Ruler |
| This is a drawing of a leaf. The drawing on the right, which was a plant cell, was magnified. What is the magnification? | x10 |
| What is the equation to work out magnification of an image? | Image size/ real size |
| A bacteria cell measures 5μm in length. Calculate the magnification of the image. (don't zoom in on the image) | To measure image size, you measure its length across with a ruler. You also need to convert it to μm
56,000μm/5μm = 11200x |
| Work out the size of the animal cell's nucleus (don't zoom in on the image) | 48,000μm/ x500 = 96μm |
| Use a scale bar to calculate the magnification factor of the image sperm cell? (don't zoom in on the image) | 51000μm/ 6μm = 8500x |
| If there was a previous answer of 8500x, what would the actual length of the sperm cell be? (don't zoom in on the image) | 45000μm/8500 = 5.3μm |
| What would the actual size of the nerve cell's nucleus be? (don't zoom in on the image) | 3000μm/500= 6x |
