AS LEVEL
B I O LO GY
,1 Cell structure ........................................................ 3
1.1 The microscope in cell studies .......................................3
Making temporary slides .............................................3
Differences between animal and plant cells ...................4
Units of measurement ...................................................6
Cell biology and microscopy ........................................7
Electron microscopy .....................................................9
1.2 Cells as the basic units of living organisms ...................13
Ultrastructure of an animal cell ...................................13
Ultrastructure of a plant cell ........................................14
Two fundamentally different types of cell .....................23
, 1 CELL STRUCTUR
1.1 T H E M I C R O S C O P E I N
STUDIES
A. compare the structure of typical animal and plant cells by making tempo
preparations of living material and using photomicrographs
Making temporary slides
1. Background information
- Biological material may be examined live or in preserved state; prepared sl
material that has been killed and preserved in life-like condition. This mat
into thin sections to enable light to pass through the structures for viewin
microscope; the sections are typically stained and ‘mounted’ on a glass slid
permanent preparation.
- Temporary preparations of fresh material have advantage that they can be
and useful for quick preliminary investigations; sectioning and staining m
carried out if required. Sometimes macerated (chopped up) material can b
examining structure of wood (xylem); a number of temporary stains are co
For example, iodine in potassium iodide solution useful for plant specime
starch blue-black and will also color nuclei and cell walls pale yellow. Dilu
methylene blue can be used to stain animal cells such as cheek cells.
- Viewing specimens yourself with microscope will help you understand and
structure more fully; this can be reinforced by making pencil drawing on g
plain paper. Remember always to draw what you see, and not what you th
see.
2. Procedure
B I O LO GY
,1 Cell structure ........................................................ 3
1.1 The microscope in cell studies .......................................3
Making temporary slides .............................................3
Differences between animal and plant cells ...................4
Units of measurement ...................................................6
Cell biology and microscopy ........................................7
Electron microscopy .....................................................9
1.2 Cells as the basic units of living organisms ...................13
Ultrastructure of an animal cell ...................................13
Ultrastructure of a plant cell ........................................14
Two fundamentally different types of cell .....................23
, 1 CELL STRUCTUR
1.1 T H E M I C R O S C O P E I N
STUDIES
A. compare the structure of typical animal and plant cells by making tempo
preparations of living material and using photomicrographs
Making temporary slides
1. Background information
- Biological material may be examined live or in preserved state; prepared sl
material that has been killed and preserved in life-like condition. This mat
into thin sections to enable light to pass through the structures for viewin
microscope; the sections are typically stained and ‘mounted’ on a glass slid
permanent preparation.
- Temporary preparations of fresh material have advantage that they can be
and useful for quick preliminary investigations; sectioning and staining m
carried out if required. Sometimes macerated (chopped up) material can b
examining structure of wood (xylem); a number of temporary stains are co
For example, iodine in potassium iodide solution useful for plant specime
starch blue-black and will also color nuclei and cell walls pale yellow. Dilu
methylene blue can be used to stain animal cells such as cheek cells.
- Viewing specimens yourself with microscope will help you understand and
structure more fully; this can be reinforced by making pencil drawing on g
plain paper. Remember always to draw what you see, and not what you th
see.
2. Procedure
