1. Quick Quiz Write down the letter(s) which answer the questions asked
All cell types
Animal
Plant
Fungal
Bacterial
1. Which cells contain ribosomes?
2. Which cells contain plasmids?
3. Which cells contain vacuoles?
4. Which cells contain a cell wall made of cellulose?
5. Which cells have mitochondria?

2. Quick Quiz Write down the letter(s) which answer the questions asked
Plasmid
Ribosome
Nucleus
6. Site of aerobic respiration?
7. Site of protein synthesis?
8. Controls cell activities?
9. Site of photosynthesis?
10. Only found in bacterial cells?

3. National 5 Cell Biology
Viewing Cells

4. We are learning to:
Describe how to use a light microscope to view cell samples
Explain the use of stains when viewing cells through a light microscope
Select a suitable stain to view different cells under a light microscope
Calculate cell length and breadth when viewed through a microscope

5. What I'm looking for:
Focus microscope onto a prepared slide to view different cells
Prepared slide of cheek and onion cell
Drawing of cells as viewed through a microscope
Calculate cell size

6. Viewing Cells
Watch the video “How to use a microscope”

7. Viewing Cells Collect Microscope 2 slides 2 coverslips Cotton bud
Tweezers
Stains
Dropper
Onion sample

8. Rub cotton bud against inside of your cheek
Method
Rub cotton bud against inside of your cheek
Rub cotton bud against slide
Put a drop of Methylene blue stain on a slide
Place a cover slip on the drop of stain, lowering it gently using the cotton bud
Observe your cells under a microscope
Draw a diagram in your jotter
Using a similar procedure make slides of different cells.
Safety Cautions
PLACE ALL COTTON BUDS IN WASTE BEAKER.
DO NOT HANDLE ANY COTTON BUDS OR SLIDES OTHER THAN YOUR OWN!!
BE CAREFUL – METHYLENE BLUE CAN STAIN CLOTHES!!
SLIDES ARE MADE FROM THIN GLASS.
TAKE CARE WHEN HANDLING

9. Cheek cells

10. Elodea

11. Red onion cells
Yeast cells

12. Stains Cells are viewed using a microscope
Stains must be added to view the parts of a cell clearly
__________ solution used for plant cells
____________ ____ used for animal cells
IODINE
METHYLENE BLUE

13. Total Magnification
Eyepiece Lens
Objective Lens

14. Eyepiece
Objective
Magnification
Actual Size
Apparent size
10x
100x
0.1mm
10mm 5x
20x
0.01mm
50x
5mm
800x
0.02mm
30x
900x
0.001mm
400x
0.04mm

15. Eyepiece
Objective
Magnification
Actual Size
Apparent size
10x
100x
0.1mm
10mm 5x
20x
0.01mm
1mm
50x
500x
5mm
40x
800x
0.02mm
16mm
30x
900x
0.001mm
0.9mm
400x
0.0001mm
0.04mm

16. Calculating cell size THINK!
How could you calculate the average length of theses cells?

17. Calculating cell size Find out the average cell length and breadth
5 cells across 2mm
2/5 = 0.4mm
Average cell breadth
10 cells across 2mm
2/10 = 0.2mm
2mm

18. I can: Describe how to use a light microscope to view cell samples
Explain the use of stains when viewing cells through a light microscope
Select a suitable stain to view different cells under a light microscope
Calculate cell length and breadth when viewed through a microscope