Investigating Cells Flashcards
What is an independent variable?
What is a dependent variable?
What is a control variable?
Independent variable - the variable you change
Dependent variable - the one that changes and that is being measured
Control variable - the ones that are kept the same
What is the typical diametre for a plant cell?
What is the typical diametre for an animal cell?
What is the typical size for a prokaryotic cell?
Plant cell - 0.1 mm in diameter
Animal cell - 0.02 mm in diameter
Prokaryotic cell - 0.002 mm long
Order these cells depending on their size (largest to smallest)
Animal cell
Prokaryotic cell
Plant cell
Plant cell - 0.1 mm in diameter
Animal cell - 0.02 mm in diameter
Prokaryotic cell - 0.002 mm long
How many… in 1 metre
a. centimetres (cm)
b. millimetres (mm)
c. micrometres
d. nanometres (nm)
Centimetres - 100 - 1 x 10^2
Millimetres - 1 000 - 1 x 10^3
Micrometres - 1 000 000 - 1 x 10^6
Nanometres - 1 000 000 000 - 1 x 10^9
What unit are cells often given in?
Micrometres
What is resolution?
The ability to see 2 or more objects as separate objects.
When was the light microscope developed?
In the late 16th century
What did the light microscope allow scientists to see?
It allowed them to have a greater resolution than the human eye and to see plant, animal and bacterial cells
However, they couldn’t see some sub-cellular structures
In what year did scientists first use an electron microscope
In 1933, scientists first began to use electron microscopes
What does an electron microscope do?
It passes electrons through the specimen giving much better resolution, rather than just passing light though
With an electron microscope you have better resolution. Why is this useful?
Scientists can study and find out how mitochondria and chloroplasts work
Ribosomes and be seen and be studied
What is the magnification?
It is how many times larger/smaller the image is than the real object.
What is the formula to find maginification
magnification = size of image
———————
size of real object
