Cell Reproduction

Why Cells Divide Cell death Repair of injury Growth/development Maintains cell size

Cell cycle Interphase(Preparation for division) – Growth G1 – DNA replication S – Spindle fibers and centrioles forming G2 Mitosis Cytokinesis

Mitosis Nuclear division 4 stages – Prophase – Metaphase – Anaphase – telophase

Mitosis Asexual reproduction in somatic cells (body cells) Parent cell splits to make two identical daughter cells. (same number of chromosomes as parent cell) Some organisms reproduce asexually such as:

Cell Cycle

Interphase-Resting and Preparation G1 S G2

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis-division of cytoplasm

Regulation of the cell cycle Varies with type of cell Involves proteins and enzymes Cyclins bind to enzymes, cyclin-dependent kinases Checkpoints monitor for DNA damage and for correct division of chromosomes

Cancer Uncontrolled cell growth and division of cells Failure of regulation of the cell cycle Causes Risks Prevention genetics

Apoptosis Programmed cell death examples

Stem cells Embryonic adult

Meiosis Need for sex cells (gametes) with half the original chromosome number. 2 divisions

Meiosis Meiosis IMeiosis II

MitosisMeiosis Function Location in Body Number of Daughter Cells Change in Chromosome Number (Beginning/End) Number of Phases Number of Cell Divisions Difference in DNA Between Parent Cell and Daughter Cells

Mitosis vs. Meiosis e.html e.html