Topic 1.2. Cells: The basic units of life
Introduction
All living organisms contain cells.
Tissue: A group of similar cells with a common
function.
Organ: A group of different tissues with a
common function.
System: Different organs with a common
function.
Organism: Different systems working together.
Microscopes and lenses developed over the years
and allowed scientists to create a “cell theory”.
According to the cell theory:
1) Every organism is made up of cells.
2) Every cell comes from another cell.
, Structure, use and care of the microscope.
Magnification (Using a microscope)
, Magnification of the microscope = magnification of
eyepiece X magnification of the objective lens.
EXAMPLE
Eyepiece= 10X
Objective lens = 40X
Total magnification is = 10X x 40X = 400X
Total magnification Objective Eyepiece
lens lens
400X 40X 10X
800X 5X
600X 60X
120X 15X
Introduction
All living organisms contain cells.
Tissue: A group of similar cells with a common
function.
Organ: A group of different tissues with a
common function.
System: Different organs with a common
function.
Organism: Different systems working together.
Microscopes and lenses developed over the years
and allowed scientists to create a “cell theory”.
According to the cell theory:
1) Every organism is made up of cells.
2) Every cell comes from another cell.
, Structure, use and care of the microscope.
Magnification (Using a microscope)
, Magnification of the microscope = magnification of
eyepiece X magnification of the objective lens.
EXAMPLE
Eyepiece= 10X
Objective lens = 40X
Total magnification is = 10X x 40X = 400X
Total magnification Objective Eyepiece
lens lens
400X 40X 10X
800X 5X
600X 60X
120X 15X
