1. Cell Structures Involved in Cell Division
Section 2.2
BC Science Probe 9
Pages 39-41

2. Cell Structures Involved in Cell Division
Quick Review:
Cells can be eukaryotic
Have a nucleus surrounded by a membrane
Animal and plant cells fit into this category

3. Cell Structure Involved in Cell Division
Quick Review:
Or cells can be prokaryotic
Have no
nucleus
These are
bacteria

4. Cell Structures Involved in Cell Division
Both prokaryotic cells and eukaryotic cells have to undergo cell division.

5. The Nucleus The nucleus acts as the control centre of the cell.
It directs all cell activities including cell division.

6. The Nucleus
The nuclear membrane allows some materials to pass into and out of the nucleus.

7. The Nucleus Chromosomes
The nucleus contains the material that directs all of the activities of the cell in structures called chromosomes.
Nearly all human
cells have 23 pairs.

8. The Nucleus Chromosomes Chromosomes are made of DNA and protein.
DNA is a very long molecule that looks like a twisted ladder.
The DNA provides the directions for everything that happens in the cell, including cell division to repair worn and damaged cells.

9. Nucleus Nucleolus The nucleolus is also found in the nucleus.
It is the site of production and assembly of the ribosomes.
Once the ribosomes are
put together, they
move out into the
cytoplasm.

10. Ribosomes and Endoplasmic Reticulum
Tiny organelles in the cytoplasm
Make proteins that the cell needs in order to work properly.
They can be free in the
cytoplasm, or attached
to the endoplasmic
reticulum.

11. Ribosomes and Endoplasmic Reticulum
A.K.A. – the ER
A series of tubes and flattened sacs that transport materials throughout the cell.
If it has ribosomes attached to it = Rough ER
Used to transport protein throughout the cell.
No ribosomes = Smooth ER
Used to manufacture and transport fats in the cell.

13. Cytoplasm The cytoplasm is inside the cell membrane.
Inside the cytoplasm are tiny tubes called microtubules.
These allow for movement of organelles in the cell.
They also provide support for the cell.

14. Cytoplasm Centrioles are organelles made of special microtubules.
They are found in
animal cells.
They are active
during cell division.