1. Cells Lesson 2

2. Starter
A reminder about microscopes from lesson 1? Click ↑ (2 mins) They all make things look bigger!
Explain to pupils that these things all make things look bigger than with the naked eye 2

3. Learning outcomes By the end of this lesson: All pupils can:
use a microscope safely and successfully
make a drawing and peer assess using success criteria
Name the basic parts of a cell
Most pupils can:
recall functions of each part
describe the differences between a cell, tissue, organ and system
can calculate magnification
Some pupils can explain ‘cell theory’

4. What is the difference between these two groups?
Then ask – “Why do we call some living and some non-living?” 4

5. Movement
Reproduction
Sensitivity
Growth
Respiration
Excretion
Nutrition

6. Movement Reproduction Sensitivity Growth Respiration Excretion
Nutrition
Living things do all of these.
Non-living things do not.

7. What are living things made from?
All living things are made from cells.
Cells are the building blocks for every living organism – even me and you!
This is called cell theory.
As cells are very small, we can only see them with the help of a microscope.

8. Festuca glauca [flower]
Plants – grasses
magnification x10
Festuca glauca [leaf]
Festuca glauca [flower]

9. Festuca glauca [flower]
Plants – grasses
magnification x60
Festuca glauca [leaf]
Festuca glauca [flower]

10. Plants – magnification x10
Bottom
Top
Pansy [flower]
Golden hop [leaf]

11. Plants – magnification x60
Kerria japonica [top]
Golden hop

12. Plant tissue – magnification x60
Crassulacean leaf [ts] x60
Dicotyledonous root [ts] x60

13. Plant tissue – magnification x200
Crassulacean leaf [ts] x200
Dicotyledonous root [ts] x200

14. Animal tissues – magnification x10
Entire eye x 10 [an organ]
Cerebellum [brain] x 10

15. Animal tissues – magnification x60
top
back
front
Entire eye x60
Cerebellum [brain] x60

16. Animal tissues – magnification x200
Cerebellum [brain] x200

17. Responsible use of microscopes
Microscopes are fragile and delicate:
They should always be carried with two hands: one underneath and one holding the curved part of the body.
You should not touch the lenses.
Persistent mistakes include:
holding the microscope with one hand
focussing down onto the slide and breaking it
turning the objective lens around and crashing into the slide
forgetting to mop up excess liquid.

18. How to use a microscope Now follow the instructions below carefully.
Make sure you have selected the low power objective lens (it’s the smallest).
Look down the eyepiece and adjust the mirror until it is as light as you can get it.
Move the focussing knob until the objective lens is as far down as it will go.
Put your slide on the stage and secure it with the stage clips.
Using the focussing knob, move the objective lens slowly up. Until you can see something. (You will need to keep looking down the eyepiece as you do this).
When you think you can see something, check with the teacher before drawing what you see.
When you have finished, remember to remove the slide from the microscope before packing it away.

19. Rules for microscope drawing:
Write a clear heading.
Use a sharp HB pencil.
Draw firm, continuous lines and avoid using too much shading.
Include the magnification (see next slide as to how to do this)
Draw label lines with a ruler. These must not touch the structure they are labelling and should not cross each other.
Write labels horizontally on the page and arrange them neatly around the drawing.

20. List the mistakes in diagram b

21. Microscopes, magnification and scale
On the next slide are photographs of a ruler at different
magnifications.
This will help you work out the size of the objects on
other slides.

22. Magnification Magnification x60 Intervals in mm Magnification x10
Interval is 1 mm

23. magnification of OBJECTIVE lens x magnification of EYEPIECE lens
Calculate the total magnification and write it on your
drawing:
Look at this short video clip:
– 1 min 55 s; cell structure and function
Total magnification =
magnification of OBJECTIVE lens x magnification of EYEPIECE lens

24. Label the parts of the animal cell24

25. Label the parts of the animal cell
Nucleus
Cell Membrane
Cytoplasm 25

26. The cell – a living factory!

27. What does each part do?

28. Label the parts of a typical plant cell28

29. Label the parts of a typical plant cell
Cell Membrane
Vacuole
Cell Wall
Nucleus
Chloroplast
Cytoplasm 29

30. Peer assessment Write a clear heading. Use a sharp HB pencil.
Draw firm, continuous lines and avoid using too much shading.
Include the magnification.
Draw label lines with a ruler. These must not touch the structure they are labelling and should not cross each other.
Write labels horizontally on the page and arrange them neatly around the drawing.

31. Functions of the cell parts extra information on this link: http://www
Cell wall
Cell membrane
Vacuole
Nucleus
Cytoplasm
Chloroplasts
Maintains shape of cell
Allows substances to enter and leave the cell.
Contains cell sap and water
Controls what happens
in the cell.
Is the site of cell reactions
Contains green chlorophyll for making food 31

32. Two songs/rap that may help you remember in the future: http://www
Two songs/rap that may help you remember in the future: – 2 mins 11 s; cell song – 1 min 23 s; plant and animal cell rap

33. From cells to systems
This activity introduces some key ideas about the building
blocks of life.
We will revisit some of the ideas in future lessons.
Click on the link:

34. Extension videos
advanced animation of structure and function of the cell
(first 3 mins)
17 mins 12 s; evolution of the eukaryotic cell