1. Chapter 8 (Part 1): Mitosis Cell Division: Asexual Reproduction 8.1 – 8.2; Pgs. 126-127 Objective: I can describe the difference between how prokaryotic cells and eukaryotic cells divide. I can also describe different DNA: chromatin vs. chromosome.

2. Why do Cells Divide? (Mainly for) Reproduction (property of …): spread DNA (genes) to continue species But other specific reasons for different organisms Multicellular Organisms Replace cells that have died (heal wounds/injuries) To help organism grow (another prop. of life) Unicellular Organisms Reproduction (how else have more?)

3. Prokaryotes vs. Eukaryotes No Nucleus Simple cell cycle DNA in a loop: 1 single circular chromosome Division is called: Binary Fission Has Nucleus Complex Cell Cycle DNA in chromatin and/or chromosomeS Division is called: Mitosis + (Cytokinesis)

4. Binary Fission Mitosis

5. Mitosis: Overview Mitosis is made up of 4 phases Prophase = prepare Metaphase = middle Anaphase = split Telophase = wrap-up Eukaryotic Cell Cycle: Overview Interphase: growing stage (between cell division) G1 = Cell Grows (G = grow) S = DNA replicates (S = synthesize new DNA) G2 = Prepares for division (replicate organelles) Cytokinesis: cell splits (cytoplasm divides) = division of nucleus (karyokinesis)

6. Types of Reproduction DNA must be copied to have full set for each cell = replication (NOT reproduction) One cell forms two daughter cells For both binary fission and mitosis, daughter cells are genetically identical…so what type of reproduxn? Binary Fission and Mitosis = asexual reproduction Meiosis = cell division to prepare for sexual reproduction

7. Intro to DNA Details Type of nucleic acid (macromolecule) In the shape of a double helix (from a distance…) Sequence of nucleotides (nitrogenous base: ACTG) determines traits (hidden in code) ACTG = complementary base pairs (helps replicate) When DNA replicates, 50% old, 50% new (more later…) Sections of DNA = genes (hold specific info) Single DNA molecule can hold 140 million nucleotides (5 centimeters in a straight line) Nucleus is about 1 micrometer (10,000x smaller)

8. Packaging DNA Chromatin = DNA wrapped up with proteins Chromosome = chromatin further condensed and wound into a structure Looks like a rod or an “X” (butterfly) 1 chromosome made of 1 DNA molecule

9. Chromosome Coiling DNA wraps around proteins called histones Group of 8 histones w/ DNA = nucleosome Nucleosomes coil up into a solenoid This is what chromatin is made out of

10. Chromosome Coiling cont’d Solenoid can loop around scaffold protein Forms width of chromosome

11. http://www.biostudio.com/demo_freeman_dna_coiling.htm http://www.dnai.org/c/index.html http://www.youtube.com/watch?v=OjPcT1uUZiEhttps://www.youtube.com/watch?v=N5zFOScowqo

12. Chromatin vs. Chromosome You know the difference, but why does cell change DNA: chromatin  chromosome? Hint: Happens for mitosis Chromosomes easier to move and divide evenly so both cells have same DNA

13. Chromosome Parts Chromatid = “Half chrmsme.” Has full amount of DNA Sister chromatids identical 2 sister chromatids = doubled chromosome  Preparing for mitosis Centromere = center Connects sis. chromatids “Marker” to count chromosomes Telomere = edges (factor in aging)