Cell Division

How is DNA Packaged? As you watch the video clip, define the following terms: Histone Nucleosome Chromatin Chromosome

Cell Division Vocabulary Centriole Centromere Chromosome Chromatid Chromatin Cytokinesis Diploid Gamete Haploid Meiosis Mitosis Somatic cells

Centriole Chromatid Chromatin Centromere Cytokinesis Chromosome Cell organelle that helps separate chromosomes during mitosis Centromere the “center” of a chromosome Chromosome X-shaped structure made of condensed DNA Chromatid One half of a chromosome Chromatin DNA in a loose, less condensed form Cytokinesis Division of cytoplasm

Meiosis Diploid Gamete Mitosis Somatic cells Haploid Divides a diploid (2n) cell into a haploid (n) cell Necessary for sexual reproduction Mitosis Cell division Somatic cells Body cell (includes all but gametes) Diploid Cell having 2 copies of each chromosome “2n” Gamete Sex cell Egg or sperm Haploid Cell having only one copy of each chromosome “n”

Cell Cycle Cells go through a predictable pattern of growth/development and replication Interphase Gap 1- cell growth Synthesis- DNA is replicated Gap 2- cell growth Mitosis Prophase, Metaphase, Anaphase, Telophase, Cytokinesis

What Happens When Cells Can’t Stop Dividing? Read this passage on cancer cells Why is cancer cell division compared to “a car moving without having pressure applied to the gas pedal”? What is the role of estrogen in a normal cell? What is “contact inhibition”? Why is this important for normal cell growth? Why do cancer cells often contain mutated DNA?