Presentation on theme: "Cell Division Mitosis Chapter 10. Why do cells divide, rather than continually grow forever? The larger a cell becomes, the more demands the cell places."— Presentation transcript:
Cell Division Mitosis Chapter 10
Why do cells divide, rather than continually grow forever? The larger a cell becomes, the more demands the cell places of its DNA. The cell also has more trouble moving enough nutrients and wastes across the cell membrane.
Division of the Cell Before it becomes too large, a growing cell divides forming two daughter cells. The process by which a cell divides into new daughter cells is called cell division. Before cell division occurs, the cell replicates, or copies, all of its DNA. Thus, each daughter cell gets one complete set of genetic information.
Cell Division Cell division is complex and occurs in 2 main stages: –Mitosis-division of cell nucleus –Cytokinesis-division of cytoplasm Genetic information is carried by chromosomes. –Before cell division each chromosome is replicated, or copied forming two identical sister chromatids, which will be separated from each other when the cell divides.
The Cell Cycle The cell cycle is a series of events that cells go through as they grow and divide. During the cell cycle, the following happens: Cell grows (interphase) Cell prepares for division (interphase) Cell divides to form 2 daughter cells (each of which further divide) (cell division)
Events of the Cell Cycle Interphase –G 1 phase Cell grows (increases in size and makes new proteins and organelles) –S phase Replication of chromosomes/DNA synthesized –G 2 phase Organelles and molecules needed for cell division produced.
Mitosis (M phase) When the events of the G2 phase are completed, the cell is ready to enter the M phase and begin cell division. The events of mitosis are divided into four phases: –Prophase –Metaphase –Anaphase –Telophase
Prophase 1 st phase of mitosis where: –Centrioles take their place at opposite sides of the cell –Spindle fibers form –Chromatin coils to form chromosomes –Nuclear envelope breaks down