Download Cell Structures Involved in Cell Division

Cell Structures Involved in Cell
Division
Section 2.2
BC Science Probe 9
Pages 39-41
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
Cell Structure Involved in Cell Division
• Quick Review:
– Or cells can be prokaryotic
• Have no
nucleus
• These are
bacteria
Cell Structures Involved in Cell Division
• Both prokaryotic cells and eukaryotic cells
have to undergo cell division.
The Nucleus
• The nucleus acts as the control centre of the
cell.
• It directs all cell activities including cell
division.
The Nucleus
• The nuclear membrane allows some materials
to pass into and out of the nucleus.
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.
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.
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.
Ribosomes and Endoplasmic
Reticulum
• Ribosomes
– 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.
Ribosomes and Endoplasmic
Reticulum
• 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.
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.
Cytoplasm
• Centrioles are organelles made of special
microtubules.
– They are found in
animal cells.
– They are active
during cell division.