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Cell Division
Cell Division Notes - Review
| Term | Definition |
|---|---|
| Cell Division | Process by which a cell divides into 2 new cells |
| Cells need to divide | Living things grow by producing more cells repair of damaged tissue If a cells gets too big, it can not get enough nutrients into the cell and waste out of the cell |
| Parent Cell | The original cell; 2 new cells are called DAUGHTER cell. |
| Before Cell Division occurs | The Cell copies (replicates) all of its DNA, so each daughter cell gets complete set of GENETIC INFORMATION from parent cell. |
| Daughter Cell | Each daughter cell is EXACTLY like the parent cell - same kind and number of CHROMOSOMES as the original cell |
| Unicellular Organisms | Reproduce by means of cell divisions- called ASEXUAL REPRODUCTION. |
| DNA | Located in the NUCLEUS and controls all cell activities including cell division |
| Chromatin | Long and thread-like DNA in a non dividing cell |
| Chromosome | DOUBLED, COILED, short DNA in a dividing cell. |
| Chromosome consist of two parts | Chromatid and Centromere |
| DNA need to change from Chromatin to Chromosomes | More EFFICIENT division |
| CENTROMERE | 2 identical sister chromatids attached at an area in the middle |
| Chromosome Number | Every organism (Human, Dog) has its own SPECIFIC NUMBER of chromosomes. |
| Cell Cycle | Series of events cells go through as they GROW and DIVIDE |
| Cell prepare for division | Cell GROWS, prepares for division, then DIVIDES to form 2 daughter cells - each of which then begins the cycle again. |
| Interphase is divided into 3 phases | G1 - cells increase in size and synthesize new proteins and organelles S -synthesis of DNA (DNA replication) G2 - organelles and molecules required for cell division are produced. |
| Somatic cells | an organism that have the SAME kind and NUMBER of chromosomes. |
| Interphase | Period of cell GROWTH and DEVELOPMENT |
| Occurs during Interphase | DNA COPY (replication) occurs during interphase The cell grows, carries out normal cell activities, replicates all other ORGANELLES Interphase is where the cell spends most of its lifecycle. |
| Mitosis | Division of the nucleus into 2 nuclei, each with the same number of chromosomes |
| Mitosis occurs | In ALL the SOMATIC (body) cells. |
| Why does Mitosis occurs | So EACH new DAUGHTER cell has nucleus with a complete set of chromosomes. |
| 4 phases of nuclear Division (mitosis), directed by the cell's DNA (PMAT) | 1) Prophase 2) Anaphase 3) Metaphase 4Telophase |
| Cell Cycle | When cell become old or damaged, they die and are replaced with NEW cells. |
| Cell Division Control | DNA Controls ALL cell activities including cell division. |
| Cells loose control | Loose the ability to control their rate of cell division - the DNA of these cells has become damaged or changed (mutated) |
| Tumors | Super- dividing cells form masses |
| Cytokinesis | the DIVISION of the rest of the cell (CYTOPLASM and ORGANELLES) after the nucleus divides. |
| Animal Cell | the CYTOPLASM pinches in |
| Plant Cell | a CELL PLATE forms |
| After mitosis and cytokinesis | The cell returns to INTERPHASE to continue to grow and perform regular cell activities |
| Benign Tumors | are not cancerous - these cell do not spread to other parts of the body. |
| Malignant Tumors | are cancerous - these cells break loose and can invade and destroy healthy tissue in other parts of the body called metastasis |