1. Mitosis!!!
Cycle 3: Change

2. Remember…. Cells are made up of organelles…
Cells take in and release energy and materials….
Some cells are specialized cells (only perform a certain job)….

3. Cell Division Cell division occurs in all organisms.
Unicellular organisms reproduce through cell division and multicellular organisms need it for growth, development and repair.
You are growing because your cells are dividing, which makes new cells and makes you grow!

4. Cell Cycle
In order for new cells to be made, cells have to go through the cell cycle (similar to our “life cycle”)-Eukaryotic Cell only!!! Remember Prokaryotes have no nucleus!
The cell cycle consists of two main phases:
Interphase
Mitosis and Cytokinesis

5. Interphase
1. The part of the cell cycle in which the cell is growing and is NOT dividing!
In addition to growing, the cell carries out it’s normal activities such as taking in materials and getting rid of waste.
2. Inside the nucleus, the cell’s DNA is being copied-2 copies of each chromosome are made before mitosis starts.

6. DNA
DNA: chemical that contains information for an organisms growth and functions. Deoxyribonucleic Acid.
In eukaryotic cells, the DNA is found in the nucleus and in prokaryotes it is in the cytoplasm.

7. Chromosomes
DNA is wrapped around proteins like thread around a spool and compacted into structures called chromosomes.

9. Terms to Remember…
Centrioles: Little tubes made up of microtubules (protein fibers/strands)
Nuclear Envelope: Surrounds nucleus
Chromatin: Unwound DNA
Chromatid: Legs of the chromosome
Nucleolus: Little blob inside the nucleus where ribosomes are made

12. Mitosis: (4 Stages) Prophase 1st Stage
Centrioles move towards opposite ends of the cell (poles).
As they separate, spindle fibers (come from the centrioles) between them grow and keep them connected (like if there were a string in between them).
The nucleolus and the nuclear envelope disappear.
Chromatin coils up and makes chromosomes (they couldn’t get out if the above didn’t disappear!).

15. Mitosis: Metaphase
Metaphase (means “meet in the middle”: chromosomes pulled by spindle fibers so they line up in the middle of the cell (centrioles are at the N and S pole with the chromosomes lined up along the equator).

17. Mitosis: Anaphase
Anaphase: Each sister chromosome gets separated (x’s turn to v’s) and go to opposite poles of cell.
The chromosomes separate by tearing apart at the centromere.

19. Mitosis: Telophase
Telophase: The chromosomes move in sets at the two poles. • The chromosomes begin to uncoil back to chromatin and look like they did during interphase. • A nuclear envelope reforms around each chromosome set, the spindle disappears, and the nucleolus reforms. Nuclear division by mitosis is complete at this point.

21. Cytokinesis
Cell curves in and splits into two identical daughter cells.
Each one goes into Interphase.
Differs slightly in plant and animal cells.