Cell Division Chapter 8 pg 144-151

Most important part of cell… The instructions, DNA Macromolecule – Nucleic Acid made of nucleotides – 4 different types DNA is organized into chromosomes Like wrapping christmas lights When they are copied they are held together by a centromere until they can be divided safely

Chromosome Numbers Some chromosomes determine the sex of an organism; sex chromosomes Can carry other genes Autosomes are non sex chromosomes All organisms have a different number of chromosomes Humans = 46 Cat = 32 Dog = 78 Lettuce = 18

Chromosome Numbers Sexual vs Asexual reproduction: Two or one parents Two copies of everything or one You get instructions on how to make your nose from Mom AND Dad – the SAME object but a different brand Both give you a cell phone but one is an iphone and the other is a droid These are called HOMOLOGOUS CHROMOSOMES

Karyotype – a picture of your chromosomes Can detect disorders Identify male or female Diploid – having two sets of chromosomes 2n Haploid – having one set 1n Humans Diploid = 46 Haploid = 23 23 from MOM + 23 from DAD = 46 More or less = bad

Cell Division Asexual Reproduction is called Binary Fission Occurs in prokaryotic organisms In eukaryotes, (us), there are two types of cell division Mitosis – occurs for growth and repair Meiosis – occurs for sexual reproduction

Cell Cycle 5 parts G0 – cells just are; no division G1 – growth S – synthesis of DNA G2 – growth and preparation M – Cell Division In Mitosis: Prophase, Metaphase, Anaphase, Telophase Cytokinesis – final division of the cell G0 – cells just are; no division

Mitosis Prophase- nucleus dissolves, Spindle forms between centrioles, DNA forms into chromosomes Metaphase- chromosomes line up in middle, centrioles make it to poles Anaphase- chromatids separate and move, cell starts to pinch Telophase- chromosomes reach poles, spindle dissolves, nucleus forms, Cytokinesis- cytoplasm finally divides

30 Words Prophase Metaphase Anaphase Telophase G0 phase G1 phase Vocabulary to include: Prophase Metaphase Anaphase Telophase G0 phase G1 phase S Phase G2 Phase M Phase Binary Fission Mitosis Meiosis Interphase Cell Cycle Cytokinesis Additional Vocabulary: Centrosomes Centrioles Spindle Fibers Cleavage Furrow Cell Plate Chromosome Sister Chromatids Centromere Chromatin Autosome/Sex Chromosome Haploid Diploid Homologous Chromosomes Karyotype 30 Words