Cell Cycle: Cell Division by Mitosis

Cell Cycle

Cell Cycle G1 - ___________________________________________________________ S - ____________________________________________________________ G2 - ___________________________________________________________ M - ____________________________________________________________

Cell Cycle   What does the cell spend more time doing? Growing or dividing? _____________________________________

So why do cells divide? What are some reasons that cells would need to divide through mitosis? _________________________________________ _________________________________________

What happens during this phase? Draw a picture of this phase Interphase During interphase the cell grows and copies its chromosomes in preparation for cell division (mitosis). Fill out the table as you go: Phase What happens during this phase? Draw a picture of this phase Interphase

Prophase During prophase the chromatin condenses into chromosomes. These chromosome consist of two sister chromatids.

Metaphase During metaphase the chromosomes line up along the metaphase plate (the middle of the cell).

Anaphase During anaphase the sister chromatids of each chromosome are pulled away from each other toward opposite sides of the cell. The sister chromatids are now each a chromosome.

Telophase During telophase two daughter nuclei form in the cell and the chromosomes become less condensed. Cytokinesis occurs when the cytoplasm divides and two genetically identical daughter cells are formed.

Video of mitosis

What about the DNA? Since cells copy their DNA in the S phase, the two daughter cells made through mitosis have the same number of chromosomes as the original cells.

What about the DNA? Elephant cells contain 56 chromosomes. If an elephant cell divides by mitosis, how many chromosomes will the two daughter cells have? _______

Review Questions What is cell division? Give an example of when a cell might need to go through mitosis (when new cells would need to be made) If a cell that has 46 chromosomes goes through mitosis, how many chromosomes will the two new daughter cells have? Briefly describe what happens in each phase of the cell cycle (Interphase, Prophase, Metaphase, Anaphase, Telophase) How is cancer related to mutations?