Basic components of living systems Flashcards
Magnification formula
Magnification = image size / actual size
Why are cells stained before being viewed under a light microscope?
Staining increases colour contrast between different sub-cellular structures and organelles, making them more visible and easily identifiable
Eyepiece graticule
A glass disc placed on the eyepiece lens, marked with a fine scale from 1-100
What is a stage micrometer?
A microscope slide with a very accurate scale in micrometers engraved on it
Rules of scientific drawing
- line, pencil drawings only
- no unnecessary detail/shading
- title and magnification clearly stated at top
- labels drawn with horizontal lines, touching the edge of the desired feature
Magnification
How many times larger the image is than the real object
Resolution
The ability to see close objects as separate entities
What is the function of the nucleus?
- contains genetic information (DNA)
- controls metabolic activities of the cell
What is the nucleolus?
Area within nucleus responsible for producing ribosomes
What is the function of mitochondria?
Site of ATP production in the final stages of aerobic respiration
Vesicles
Membranous sacs which transport materials in the cell
Lysosomes
Specialised vesicles which contain hydrolytic enzymes to break down waste products
Functions of the cytoskeleton
- controls cell movement
- moves organelles within the cell
- provides mechanical strength to the cell
Three types of cytoskeletal filaments
- microtubules
- microfilaments
- intermediate fibres
Give two types of extensions from cells
- flagella
- cilia
