Biology 1 Flashcards
What are microscopes used for?
To observe small objects in detail
What do animal cells contain?
Nucleus
Cytoplasm
Cell membrane
Mitochondria
What do plant cells also contain (in addition to the animal cells)?
Chloroplasts
A vacuole
Cell wall
What do specialised cells have?
Specialised cells have a shape and structure suited to carry out a particular job
What is diffusion?
Diffusion is the movement of particles from high concentration to low concentration
What is a uni-cellular organism?
It contains only one cell
What is a multi-cellular organism?
They are made up of many cells, grouped into tissues, working together to form organs that work in groups to form organ systems
What is the skeleton made up of?
Bones
What are the four important functions of the skeleton?
Support
Protection
Movement
Making blood cells
What are joints?
Joints occur where two or more bones join together
What does cartilage do?
Cartilage in joints stops bones rubbing together
What holds bones together?
Ligaments
What joins muscles to bones?
Tendons
What are antagonistic muscles?
They are pairs of muscles that work together at a joint. When one contracts the other relaxes.
How does a light microscope work?
Light shines through a specimen
A series of lenses then magnifies the image
The specimen, such as a sample of cells, must be very thin, so it needs to be supported on a thin glass slide
The slide and specimen are transparent and allow the visible light to pass through to the magnifying lenses
A microscope is very _______ and must be treated with great ______
Fragile
Care
How do you lift the microscope?
You lift the microscope with 2 hands
One on the body and one under the base
How do you adjust the objective lens?
Adjust the objective lenses so that the lowest power lens is over the hole in the stage
For the objective lenses, how do you know which is the lowest power lens?
It is the shortest, it has a red band on it and it has the number 4 on it
Why is it important to have your head at the side of the microscope when turning the coarse focusing wheel to make the gap between the stage and the objective lens as small as possible?
So you do not smash the lens into the glass
When you put the microscope slide onto the stage, what do you use to fix it on?
Clips
How do you adjust the light source on the microscope?
This can be done by turning the iris diaphragm so that the field of view is bright but not dazzling
If using a mirror and a lamp, adjust the angle of the mirror
Look down the eyepiece lens and use the coarse focusing knob to slowly move the stage _____ from the objective lens until you can see a very clear, sharp image. Adjust the __________ to clarify further.
Away
Fine focusing knob
What do you do if you need greater magnification?
Turn to a higher power objective