Cell Division Chapter 10-2

I. Cell Division A. Cell reproduction 1. Results in 2 new daughter cells

B. Purpose of cell division: 1. to grow 2. To replace old and worn out cells 3. Repair damaged cells

II. Chromosomes A. Contain genetic information 1. DNA B. Diff. organisms have a diff. # of chromosomes 1. Humans have 46 (23 from mom & 23 from dad)

C. Chromosome Structure 1. Chromatid = 1 copy of DNA 2. Sister Chromatids: 2 copies of the chromosome a) sister chromatids are held together by a centromere

centromere Sister chromatid Sister chromatid

III. The Cell Cycle A. The life cycle of a cell 1. Major events: a) Interphase (95%) b) Mitosis (5%) c) Cytokinesis M Phase M phase = cell division

The Cell Cycle M phase= cell division

B. Interphase 1. 3 phases: a) G1 Phase b) S Phase c) G2 Phase

C. Mitosis: division of the nucleus 1. 4 phases a) Prophase b) Metaphase c) Anaphase d) Telophase

D. Cytokinesis: division of the cytoplasm a) Animal cells: the plasma membrane pinches in until two separate cells are formed b) Plant cells: a cell plate forms between the two nuclei separating the daughter cells

Cytokinesis in Animal Cells

Cytokinesis in Plant Cells