Chapter 2- Cells Flashcards
What do microscopes do?
Microscopes make small objects appear bigger. With a microscope you can zoom in and see the cells that make up living things.
What are animals, plants and other living things made of?
Animals, plants and other living things are made up of tiny cells.
What is the function of a compound light microscope?
These microscopes use light and a number of lenses to form an imageThe specimen (the object being observed) is placed on a rectangular piece of glass called a microscope slide. The specimen needs to be very thin so that light can pass through it. A small, thin piece of glass called a coverslip is placed on top of the specimen. Light is made to pass through the object and the glass lenses, which bend the rays of light. A magnified image of the part of the specimen directly under the objective lens is formed..
What is a microscope called with one eyepiece?
The microscope at right has only one eyepiece; it is a monocular microscope.
What is a microscope called with two eyepieces?
Some school microscopes have two eyepieces; they are called binocular microscopes.
What are microscopes with built-in lights?
These microscopes do not have a mirror at the bottom; they have a light.
What do most microscopes have a selection of?
Most microscopes have a selection of objective lenses, and a revolving nosepiece allows the user to switch from one objective lens to another and thus change the magnification.
How can you calculate the magnification?
You can calculate the magnification by multiplying the eyepiece magnification by the objective lens magnification.
Does changing the objective lens change the size of the image?
It is important to note that changing the objective lens does not change the size of the image; it just shows a tinier part of the specimen at a greater magnification.
What can a typical school microscope magnify up to?
Typical school microscopes can magnify up to 400 times.
What is the microscope measured in?
The measurements of objects viewed under a microscope are usually expressed in microns or micrometres.
1 micron or micrometre (µm) = 0.000 001 m = 0.001 mm
What are the main rules for handling a microscope?
Rules for handling a microscope
- Always use two hands when carrying a microscope: one on the arm of the microscope and the other under the base.
- Place the microscope securely on a flat surface, away from the edge. • Never shine sunlight directly up the microscope tube. You could damage your eyes.
- Use only lens tissues to clean microscope lenses; never use your fingers.
What are the hints for using a microscope?
More hints for using a microscope •
Look down the microscope with one eye, but keep both eyes open — don’t squint.
• Begin focusing a microscope on the lowest magnification.
• Focus a microscope by beginning with the coarse focus. Look from the side and adjust the objective lens so that it is just above the microscope slide.
• Turn the coarse focus knob to move the tube up until the object comes into view.
• Turn the fine focus to make the image of the object as clear as possible.
What is a digital eyepiece?
You can take photos of microscopic objects using a digital eyepiece. This is a special digital camera that works with a microscope.
How can a digital eyepiece be viewed?
Instead of looking through the eyepiece to see the image, the digital eyepiece is connected to a computer and the image can be viewed on a computer screen. The image can be saved, annotated and manipulated in the same way as any digital photo.
What is a stage in a microscope?
Where the slide is placed
What is the function of eyepiece lens?
Used to adjust the amount of light reaching the eyepiece
What is the function of the coarse focus knob?
Makes large adjustments to the distance between the stage and the objective lens; brings the image into focus
What is the function of the fine focus knob?
Makes small adjustments to the distance between the stage and the objective lens; brings the image into focus
What is the function of the stage slide clip?
Holds the slide in place
What is the function of the mirror?
Directs the light towards the specimen
What is the function of the iris adjustment?
Used to adjust the amount of light reaching the eyepiece
What is the function of the slide?
Thin piece of glass where the specimen is placed
What is the function of the revolving nosepiece?
Can be turned to change objective lens