Section 3 Cell Division
Cell Division
Learning Intentions:
 Why is cell division necessary?
 What is cell division?
 What is mitosis?
 What are the stages of mitosis?
 How is cell division in plant cells different to that in animal cells?
Why is cell division necessary?
• Without cell division no organism would be able to reproduce, grow
or repair itself
What is mitosis?
• Mitosis is the process by which the nucleus of a cell divides into two
identical daughter cells
• Inside the nucleus there are threadlike structures called
chromosomes
• Chromosomes carry all the genetic information that is necessary for
the development of cells and survival of a living organism
• Mitosis is necessary to maintain the chromosome complement –
ensures that all cells have identical information thus ensuring that
they can perform the same function as the parent cell
What are the stages of mitosis?
• There are six stages in mitosis
1.
The chromosomes inside the nucleus uncoil and double (for
example if there were 12 chromosomes then after doubling there
would be 24 identical chromatids)
What are the stages of mitosis?
2. Chromosomes (consisting of two chromatids) coil up
What are the stages of mitosis?
3. Chromosomes line up along the equator of the cell and spindle fibres
attach themselves to the centromere of each chromosome
What are the stages of mitosis?
4. The spindle fibres pull the chromosomes apart. Each chromatid is
pulled to opposite poles of the cell by the spindle fibres
What are the stages of mitosis?
5. A nuclear membrane now forms around the chromatids and the
cytoplasm begins to divide
What are the stages of mitosis?
6.
The cytoplasm completely divides and two identical daughter cells
are formed
Mitosis animation
What is the difference between mitosis in plant cells
and animal cells?
 When the daughter cells form a
cell wall must form as well as
the cell and nuclear membrane