1. Cell structure Learning Intention:
Investigate the structure of plant, animal, fungal
and bacterial cells.
Success Criteria:
Be able to identify the main structures found in
typical plant and animal cells
typical fungal and bacterial cells
Be able to state the functions of these structures
Be able to do calculations concerning cell size and
cell growth

2. Starter Activity:
Answer the following question in your jotter.
Name three types of cells in your body.
Approximately how many cells are there in the human body?
How many cells are there in an Amoeba?

3. Answers Blood, nerve, muscle, bone, brain, liver, skin etc
100 trillion (100 million million)
One

4. UNIT ONE CELL BIOLOGY
NATIONAL 5 BIOLOGY

5. Key Area 1
Cell structure

6. Animal and plant cells Learning Intention: To review cell structure
Success Criteria:
Be able to name the structures common to animal and plant cells which are visible under a light microscope.
Be able to name the structures found only in plant cells which are visible under a light microscope.
Be able to label these on a diagram and state their functions.
Be able to calculate cell size from a picture.

7. What is a cell?
The following video clips will introduce you to the basic features of cells.
What is a cell? (BBC)
Plant and animal cell structures (BBC)
What is a cell? (Glow)

8. Examining Onion Cells Aim:
To observe and draw onion cells using a microscope.
Equipment:
Glass slide
Cover slip
Onion skin
Iodine stain
Microscope
Lamp 8

9. Method: Collect a thin piece of onion skin.
Spread the skin on a slide. The skin must not overlap.
Stain the cells by adding 2 drops of iodine stain.
Place a cover slip over the skin. Use a pencil or mounted needle to lower the cover slip gently so the air is pushed out.
Examine the cells under low then medium power. You should be able to see lots of cells arranged like bricks in a wall.
Adjust the microscope to a higher power.
Draw exactly what you see through the “field of view” using a pencil.
Label as many structures as you can see. 9

10. Onion cells in iodine
nucleus
cell wall
cytoplasm 10

11. Examining Pondweed Cells
Aim:
To observe and draw pondweed cells using a microscope.
Equipment:
Glass slide
Cover slip
Small leaf from Elodea or Cabomba
Microscope
Lamp 11

12. Method: Collect a small leaf of pondweed.
Place it in a drop of water on a slide.
Use a pencil or mounted needle to lower the cover slip gently so the air is pushed out.
Examine the cells under low then medium power. You should be able to see lots of cells arranged like bricks in a wall. Look for green chloroplasts inside the cells.
Adjust the microscope to a higher power.
Draw exactly what you see through the “field of view” using a pencil.
Label as many structures as you can see.
Return the slide and pack your microscope away carefully. 12

13. Pondweed cells
These cells are from a pondweed called Elodea.
These cells are from a pondweed called Cabomba.
What two plant cell structures can you see in the pictures?

14. Other plant cells
These cells are from a beetroot. The red dye makes it hard to see the nucleus but if you look closely you will see them.
These are the cells in the stem of a plant. Some of these cells carry water upwards to the leaves, while others carry sugars from the leaves to other parts of the plant.

15. A Typical Plant Cell cell membrane vacuole nucleus cell wall
green chloroplast
cytoplasm 15

16. Cell size calculation Numeracy!
The field of view in this picture is 0.5mm wide.
Calculate the width of one cell (clue: count the number of cells from one side to the other across the line shown).
Now estimate the cell length.
0.5mm

17. Examining Cheek Cells Aim:
To make a slide of cheek cells and draw them.
Equipment:
Glass slide
Cover slip
Cotton bud
Methylene blue stain
Microscope and lamp
Paper towel 17

18. Method:
Rub the cotton bud over the inside of your cheek to remove some of the cells.
Wipe the cotton bud over the surface of a glass slide.
Place the cotton bud in disinfectant.
Stain the cells with 2 drops of methylene blue stain.
Remove some of the stain using paper towel.
Use a mounted needle to lower the cover slip so the air is pushed out.
Draw the cells and label the structures.
Once you have finished, place the slide and cover slip in disinfectant.
Pack away your microscope carefully. 18

19. Cheek cells in methylene blue
nucleus
cell membrane
cytoplasm 19

20. Typical Animal Cell
nucleus
cytoplasm
cell membrane 20

21. Cheek cell size calculation
Numeracy!
Cheek cell size calculation
The field of view in this picture is 200 µm. (1mm=1000 µm)
Estimate the size of these cheek cells. (Clue : how many would fit across the line?)
200 µm

22. Comparison of Cell Types Copy the table and put a tick or a cross in each box. (Answers on next slide)
Structure
Plant Cell
Animal Cell
cell wall
cell membrane
nucleus
cytoplasm
chloroplasts
vacuole 22

23. Comparison of Cell Types
Structure
Plant Cell
Animal Cell
cell wall
yes no
cell membrane
nucleus
cytoplasm
chloroplasts
vacuole 23

24. Functions of cell structures
Magnified cell structures (BBC)
Each cell structure has a different job within the cell. This is called its function.
Copy the table on the next slide which summarises the functions of the main structures in plant and animal cells.

25. Large round structure containing genetic material
Description
Function
Nucleus
Large round structure containing genetic material
Controls cell activities
Cell Membrane
Very thin layer surrounds the cytoplasm
Controls the passage of substances into and out of the cell
Cytoplasm
Fluid, jelly-like material
Site of biochemical reactions
Cell Wall
Outer layer made of mesh of cellulose fibres
Provides plant cells with support
Vacuole
Fluid-filled sac in the cytoplasm
Stores water and minerals and provides extra support for plant
Chloroplasts
Disk-like structures containing green chlorophyll
Trap light energy for making food by photosynthesis 25

26. Animal and plant cells Learning Intention: To review cell structure
Success Criteria:
Be able to name the structures common to animal and plant cells which are visible under a light microscope.
Be able to name the structures found only in plant cells which are visible under a light microscope.
Be able to label these on a diagram and state their functions.
Be able to calculate cell size from a picture.

27. Starter Activity:

28. Starter Activity: E C

29. Cell ultrastructure Learning Intention:
To investigate more detailed structures in plant and animal cells
Success Criteria:
Be able to state that cell structures can be seen clearer and at higher magnification using an electron microscope
Be able to name some structures in animal and plant cells which are visible under an electron microscope
Be able to label these on a diagram and state their functions

30. The History of Microscopes
The history of microscopes (Glow)

31. Electron microscopes
Light microscopes like the ones in the lab can magnify up to 400 times. Some light microscopes can magnify up to 1000 times.
Electron microscopes use a beam of electrons instead of light. Some can magnify up to 2 million times.
This allows us to see other smaller structures inside cells.

32. Light microscope v electron microscope
Image of pollen grains under the light microscope
Image of pollen grains under the electron microscope

33. High magnification images of pollen using electron microscope

34. Animal cell under electron microscope
Many new structures can be seen in the cytoplasm that are not seen using a light microscope.

35. Plant cells under electron microscope
What is a cell? (Glow)

36. Cell ultrastructure
In the cytoplasm of plant and animal cells there are structures called mitochondria.
They are the site of aerobic respiration.

37. Mitochondria

38. Nucleus The nucleus is made up of many chromosomes.
These are not normally seen very clearly as they wound up around each other like a ball of string.
They are made of DNA and are the genetic material of the cell.
How many chromosomes are in each human cell?

39. Ribosomes
Even smaller structures can be seen in the cytoplasm called ribosomes.
They are the site of protein synthesis in plant, animal and bacterial cells.

40. Ribosomes
Ribosomes can be found free floating, or attached to membranes in the cell.
(attached to a membrane)
(free floating)

41. Cell membrane
The cell membrane can be seen in more detail when using the electron microscope.

42. Plant cell walls
Cellulose fibres
When viewed with an electron microscope, the cell wall of plant cells can be seen to be made up of fibres of a material called cellulose. Small molecules can easily pass through the spaces between the fibres.

43. Cell ultrastructure Label the handout diagram using these words :
nucleus
cytoplasm
ribosomes
mitochondria
chromosomes

44. Functions of cell structures
Match up the cell structures with their function.
Draw a table, with headings, to display this information. Use a ruler!
Site of aerobic respiration
chromosomes
ribosomes
Site of protein synthesis
Made of DNA. Contain genetic material of the cell.
mitochondria

45. Cell ultrastructure Learning Intention:
To investigate more detailed structures in plant and animal cells
Success Criteria:
Be able to state that cell structures can be seen clearer and at higher magnification using an electron microscope
Be able to name some structures in animal and plant cells which are visible under an electron microscope
Be able to label these on a diagram and state their functions

46. Starter Activity:

47. Starter Activity: C

48. Starter Activity:
Answer the following question in your jotter.
a) What cell structures are made of DNA?
b) How many of these are there in a normal human body cell?
2. What is the function of ribosomes?
3. Where in the cell are mitochondria found?
4. Which are the smallest – chromosomes, ribosomes or mitochondria?
5. What kind of microscope is needed to see these clearly?

49. Answers a) Chromosomes b) 46 Protein synthesis In the cytoplasm
Ribosomes
Electron microscope

50. Fungal and bacterial cells
Learning Intention:
To investigate the structure of fungal and bacterial cells
Success Criteria:
Be able to name the structures found in fungal cells which are visible under a microscope
Be able to label these on a diagram
Be able to name the method of reproduction in yeast
Be able to name the main structures found in bacterial cells
Be able to state the function of plasmids
Be able to do calculations of cell growth

51. Fungal cells
Fungi are a group of organisms that includes mushrooms, moulds, yeast and toadstools.
Yeast is a unicellular fungus – made of single cells.
It has cytoplasm, a nucleus and a cell wall like plant cells.
It has no chloroplasts and cannot photosynthesise.
It reproduces by ‘budding’.
Yeast cells can reproduce rapidly if they have a source of food (sugar)and a suitable temperature.

52. Looking at yeast Collect the following:
Microscope, slide, yeast suspension, dropper, cover slip.
Method
Place one drop of yeast suspension in the middle of a microscope slide, and lower on a cover slip.
View the yeast cells at low and high power. Look for cells that are budding.
Small bud forming
Yeast cell

53. Yeast cells under the microscope

54. Typical fungal cell

55. Yeast budding ( a method of reproduction)
Copy the diagram.
yeast cell

56. Uses of Yeast Brewing Industries Alternative Fuel Industries
Bread-making Industries 56

57. Bacterial cells Numeracy!
Bacterial cells are very tiny compared to other plant and animal cells. Viruses are even smaller!

58. Looking at bacterial cells
Your teacher will give you prepared slides of bacterial cells to view under the microscope.
They have been stained to show them up more clearly.
You will need to use the highest power of lens to see them clearly.
Start by focusing at low power, then increase to medium power then high power.

59. Structure of a typical bacterial cell
Here you can see that bacterial cells have some of the structures we have already seen in plant and animal cells.
These details can only be seen under electron microscope.

60. Structure of a typical bacteria
cell membrane
cell wall
plasmid (additional DNA)
Copy the diagram, labels and notes below.
cytoplasm
main DNA ring (single chromosome)
flagellum for movement (not always present)
The DNA in bacteria is not in a proper nucleus.
Instead it consists of a main ring or coil of DNA.
In addition to this, there are other smaller rings of DNA called plasmids.
Plasmids are involved in bacterial reproduction.

61. Cell Wall Structure
The cell walls that surround plant cells are made of cellulose fibres.
The cell walls that surround bacterial cells and fungal cells are not made of cellulose!

62. Reproduction in yeast and bacterial cells
Single celled organisms like yeast and bacteria reproduce by dividing into two cells.
If the conditions are right, yeast and bacterial cells can divide to make two cells once every 30 minutes. This means that the number of cells can double every 30 minutes!
What do you think would be the ideal conditions for this to happen?
Answer :
Source of food, suitable temperature, oxygen available

63. Numeracy! 30 mins 1 hour 1 hour 30 mins 2 hours 2 hours 30 mins
REPRODUCTION IN YEAST AND BACTERIAL CELLS
30 mins
1 hour
1 hour 30 mins
2 hours
2 hours 30 mins 63

64. Yeast dividing calculation
Numeracy!
Yeast dividing calculation
One yeast cell is placed in a sugar solution. It divides to form 2 cells in 30 minutes. How many yeast cells will there be after 12 hours?
How to work it out
12 hours = 24 divisions
Number doubles each division
The answer is on the next slide!

65. Numeracy! Answer = 16,777,216 yeast cells 2 4 8 16 32 64 128 256 512
1024
2048
4096
8192
16384
32768
65536
131072
262144
524288
Answer = 16,777,216 yeast cells

66. Cell variety
We have looked at the structure of typical animal, plant, fungal and bacterial cells. However, not all animal cells look the same.
The same is true of plant, fungal and bacterial cells.
The structure of each type of cell is related to its function.
Bioviewer activity
Examine the biosets provided on cell variety.
Read the notes that go with each slide.
Types of cells (Glow)

67. Cell variety challenge
Your challenge is to use your biological knowledge to identify plant, animal, fungal and bacterial cells.
Examine each of the microscope slides under the microscope. Do not uncover the label.
Look at the structures that are visible at low and high power.
Decide whether the cells are animal, plant, fungal or bacterial.
Write down the evidence that led you to your decision.
Reveal the label to find out what each type of tissue is.

68. Cell variety challenge Copy the table
Slide
Plant/animal/ fungal/bacterial
Evidence
Name of tissue A B C D E

70. C

71. Fungal and bacterial cells
Learning Intention:
To investigate the structure of fungal and bacterial cells
Success Criteria:
Be able to name the structures found in fungal cells which are visible under a microscope
Be able to label these on a diagram
Be able to name the method of reproduction in yeast
Be able to name the main structures found in bacterial cells
Be able to state the function of plasmids
Be able to do calculations of cell growth

72. Cell Variety Challenge
Your task is to produce an A5 information booklet about cell structure and function.
You must include…
Labelled diagrams of the four main cell types:
Plant – Animal – Bacterial Fungal
Describe the functions (jobs) of each labelled part.
You should include…
Examples of specialised cells from each of the four cell types.
Draw labelled diagrams of your examples and add information about how their special features make them well suited to their special functions.
You could include…
A set of ten questions at the back of your booklet about the information inside.
To help you gather information with this task you may use any text book in the classroom (Int.2, higher) and the books in the library cupboard and box. You may also use the Bioviewer slide packs and can have 10 minutes per pair on the computers for research.

73. Cell Variety Challenge
Your task is to produce an A5 information booklet about cell structure and function.
You must include…
Labelled diagrams of the four main cell types:
Plant – Animal – Bacterial Fungal
Describe the functions (jobs) of each labelled part.
You should include…
Examples of specialised cells from each of the four cell types.
Draw labelled diagrams of your examples and add information about how their special features make them well suited to their special functions.
You could include…
A set of ten questions at the back of your booklet about the information inside.
To help you gather information with this task you may use any text book in the classroom (Int.2, higher) and the books in the library cupboard and box. You can have 10 minutes each on a computer.