Cell Division The Life of a Cell

Vocabulary Terms for Mitosis Asexual Reproduction – new organism is formed from one parent cell Mitosis - cell division that ensures that each daughter cell gets an exact copy of the mother cells DNA Cytokinesis - division of the cytoplasm during cell division Chromosomes -A doubled rod of condensed chromatin

Chromatid - one half of a duplicated chromosome Centromere - area where the chromatids of a chromosome are attached Chromatin - granular material visible within the nucleus; consists of DNA. Spindle - a network of microtubules that forms during mitosis and moves chromatids to the poles Cell Equator - this is where chromosomes pair up and attach to the spindle

Before we begin, we must learn about chromosomes.

Chromosomes Humans have 46 chromosomes in their cells. Carry the material for your characteristics One chromosome has 2 chromatids Held together by a centromere

Cornell Notes To increase the number of cells so multicellular organisms can grow! The steps from one cell division to the next. What is the purpose for cell division? Define Cell Cycle

All cells must: Form - Develop Grow - Die Interphase Prophase Metaphase Anaphase Telophase Cytokinesis What do cells do in their life cycle? List the steps of the cell cycle.

Interphase (not part of Mitosis) Where the cell spend most of its life growing G1: normal cellular functions occur, cell grows S: DNA replicates, 2 copies of each chromosome G2: cell prepares for Mitosis, centrioles split Explain the stages of interphase

Centrioles

Prophase Analyze what occurs during Prophase in Mitosis Chromosomes are visable Sister chromatids form Nuclear envelope disappears Spindle fibers form from centrioles Centrioles move to opposite endes of cell Analyze what occurs during Prophase in Mitosis

Analyze what occurs during Metaphase in Mitosis Double-stranded chromosomes line up in the middle (equator) Spindle fibers attach to sister chomatids at the centromere.

Anaphase Each centromere divides as sister chromatids are pulled to opposite sides of the cell.

Telophase Chromosomes reach opposite sides Nuclear envelope forms Chromosomes uncoil Spindle fibers disappear

Cytokinesis Division of the cytoplasm 2 genetically identical cells form “Daughter” cells In animal cells, the cell membrane pinches in the middle In plant cells, a cell plate forms

Videos http://unctv.pbslearningmedia.org/resource/tdc02.sci.life.stru.dnadivide/mitosis/ http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_cell_cycle_works.html http://www.youtube.com/watch?v=ZEwddr9ho-4 (mitosis dance)