1. Source : Genetics Home Reference

2. kinetochore
Source :

3. WALT know what DNA is
DNA stands for deoxyribonucleic acid.
What is DNA made of? DNA is made up of nucleotides. Each nucleotide consist of a base molecule, a phosphate molecule and a sugar molecule.
There are four types of base:
A- adenine
T- thymine
G – guanine
C - cytosine
They are held together by a backbone made of phosphate and deoxyribose (sugar).
The double helix structure was discovered by Watson and Crick in 1953.

4. The bases always pair together in the same way, A with T, C with G.
The human genome is made of 3.2 billion bases of DNA but other organisms have different genome sizes.

5. WALT know what cell cycle is Knowledge harvest :
Where do cells come from?
Why do cells divide?
How many cells are there in your body?
How do cells know when to divide?
How many different types of cell division are there?
Source :

6. Cells Human body: 37 trillion cells (in German: 37 Billionen)
Size: 0,004 mm (~4-5 µm)
Put in line: 100 times around earth
Every second: 50 million cell die

7. Cells Every cell has its own task (hair, liver, heart, muscle, eye...)
Life of a cell:
lip: 2 weeks
liver: 8 month
Biggest human cell: female egg cell (0,12mm)
Task : Draw a double ringed circle and label the main parts of a cell cycle.

8. Cell Cycle Interphase lasts about 12-24 hours.
Mitosis – cell growth and protein production stops.
Lasts only 1-2 hours.

9. Source : Genetics Home Reference

10. Source :http://publications. nigms. nih. gov/thenewgenetics/chapter1

11. kinetochore
Source :

12. Chromatin vs chromatid vs chromosome.
46 chromosomes

13. Dna protein complex which is made up of
DNA wrapped around by proteins called histones.

14. At the beginning of the S phase of a cell division, the DNA
replicates and produces two identical copies which are held
together by the centromere. This X structure is called a sister
chromatid pair. Chromatid is a condensed version of a chromatin.

15. Chromosomes can be found in 3 forms: thread-like chromatin (during G1 of interphase), thread-like sister chromatids (during S-phase of interphase) and the condensed, visible form (during mitosis).
Source :

16. Cell Cycle Interphase lasts about 12-24 hours.
Mitosis – cell growth and protein production stops.
Lasts only 1-2 hours.

17. WALT know what mitosis is
The genetic purpose of mitosis is to produce two daughter cells that are genetically identical to the parent cell.
Reasons for mitosis – growth, regeneration/healing and replacement of dead cells. Problems with this process can seriously damage or kill cells.

18. Source : newscenter.lbl.gov

19. Task :
Draw the 5 diagrams on a blank A4 paper.
Read the text and follow the instructions given to you.
Hand in your work.

23. Viewing mitosis in onion root tips!
Using onion root cells to view mitosis
Viewing mitosis in onion root tips!

24. region of cell elongation
region of cell division
protective root cap

25. Viewing mitosis in onion root tips!
Why use onion roots?
easy to grow in large numbers
cells at the tip actively dividing
cells are in stages of mitosis
chromosomes can be stained to make them more easily observable

26. Make a squash preparation

27. Take a closer look!

32. What is mitosis?

33. Interphase
Anaphase
Prophase
Telophase
Metaphase
Cytokinesis
Stages of cell cycle : I Pray Mainly At The Church!

34. Stages in mitosis :
Prophase, Metaphase, Anaphase and
Telophase

36. Create a class drama based on mitosis
Idea for mitosis drama
Characters needed :
Nucleus-big cloth
Cell membrane – kids in dark clothes holding hands
Chromatid connected by centromeres
Chromosomes line up in centre as centrioles enter
Centrioles with same coloured jackets that can be taken off to reveal white T-shirt