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Cell Reproduction- Chapter 8 CELL REPRODUCTION- CHAPTER 8 CELL REPRODUCTION VOCABULARY- CHAPTER 8 (33 words) 1. Chromosome 2. histone 3. chromatid 4. Centromere 5. chromatin 6. autosome 7. Sex chromosome 8. homologous chromosome 9. karyotype 10. Diploid 11. haploid 12. mitosis 13. Binary fission 14. asexual reproduction 15. meiosis 16. Gamete 17. interphase 18. cytokinesis 19. Prophase 20. spindle fibers 21. metaphase 22. Anaphase 23. telophase 24. cell plate 25. Synapsis 26. tetrad 27. crossing-over 28. Genetic recombination 29. spermatogenesis 30. Independent assortment 31. oogenesis 32. Polar body 33. sexual reproduction CHROMOSOMES TIGHTLY PACKED DNA & HISTONE PROTEINS COMPRISE CHROMOSOMES. HISTONES: PROTEINS THAT DNA WRAPS AROUND TO FORM CHROMOSOMES. NONHISTONE PROTEINS CONTROL THE ACTIVITY OF DNA. CHROMOSOMES ARE MADE UP OF TWO CHROMATIDS. CHROMATIDS ARE IDENTICAL COPIES OF DNA AND PROTEINS. CENTROMERE: THE ATTACHMENT POINT FOR TWO CHROMATIDS IN A CHROMOSOME. CHROMATIN: LOOSLEY PACKED DNA & PROTEINS. CHROMOSOME NUMBERS EACH SPECIES HAS A CHARACTERISTIC CHROMOSOME NUMBER. HUMANS: 46 LETTUCE: 18 SEX CHROMOSOMES THESE DETERMINE THE SEX OF THE ANIMAL. HUMANS: MALES ARE XY, FEMALES ARE XX. SOME OTHER TRAITS BESIDES SEX ARE CARRIED ON THESE CHROMOSOMES. AN EXAMPLE WOULD BE TO MAKE BLOOD CLOTTING PROTEINS. AUTOSOMES THESE ARE THE OTHER 44 CHROMOSOMES THAT DO NOT DETERMINE ONE’S SEX. HOMOLOGOUS CHROMOSOMES THESE ARE CHROMOSOMES THAT HAVE THE SAME SIZE AND GENE ARRANGEMENT. IN SEXUALLY REPRODUCING ORGANISMS EACH PARENT GIVES ONE HOMOLOGOUS CHROMOSOME TO ITS OFFSPRING. THUS THE OFFSPRING HAS TWO COPIES OF EACH AUTOSOME. KARYOTYPE THIS IS A PHOTOMICROGRAPH OF CHROMOSOMES. THE CHROMOSOMES ARE ARRANGED BY SIZE FOR THE AUTOSOMES. THE SEX CHROMOSOMES ARE PUT NEAR THE END OF THE PICTURE. DIPLOID & HAPLOID CELLS DIPLOID CELLS (2N): THESE HAVE TWO COPIES OF HOMOLOGOUS CHROMOSOMES AND HAVE TWO SEX CHROMOSOMES. HAPLOID CELLS (1N): THESE HAVE ONLY ONE COPY OF AUTOSOMES AND HAVE ONE SEX CHROMOSOME. CELL DIVISION PROKARYOTES HAVE A CIRCULAR CHROMOSOME WHICH IS COPIED INTO TWO CHROMOSOMES AND SPLIT INTO TWO NEW CELLS THROUGH BINARY FISSION. EUKARYOTES DIVIDE ROD-SHAPED CHROMOSOMES BY MITOSIS. THIS IS ASEXUAL REPRODUCTION. CYTOKINESIS DIVIDES THE CELL’S CYTOPLASM. THE CELL CYCLE INTERPHASE IS COMPRISED OF THE FOLLOWING: G1 PHASE - OFFSPRING CELLS GROW TO FULL SIZE. S PHASE - DNA IS COPIED. G2 PHASE – THE CELL PREPARES TO DIVIDE. THE CELL CYCLE CONT. MITOSIS IS COMPRISED OF THE FOLLOWING: PROPHASE – REPLICATED CHROMOSOMES EACH MADE UP OF TWO CHROMATIDS FORM. A MITOTIC SPINDLE FORMS MADE UP OF CENTRIOLES, KINETOCHORE FIBERS, AND POLAR FIBERS. ITS JOB IS TO DIVIDE THE CHROMOSOMES. METAPHASE – CHROMOSOMES ALIGN AT THE CENTER OF THE CELL. ANAPHASE – CHROMATIDS OF EACH CHROMOSOME ARE SEPARATED. THEY ARE NOW CONSIDERED TO BE INDIVIDUAL CHROMOSOMES. TELOPHASE – CHROMOSOMES ARE AT OPPOSITE ENDS OF THE CELLS. A NUCLEAR MEMBRANE FORMS AROUND EACH NEW GROUP OF CHROMOSOMES TO FORM NEW NUCLEI. THE CHROMOSOMES TURN INTO CHROMATIN. THE SPINDLE DISSOLVES. A NUCLEOLUS FORM IN EACH NEW NUCLEUS. CYTOKINESIS THIS IS THE DIVISION OF THE CYTOPLASM. A CLEAVAGE FURROW DEVELOPS IN ANIMAL CELLS AND DIVIDES INWARD FORMING TWO NEW CELLS. A CELL PLATE DEVELOPS IN PLANTS CELLS. IT GROWS AT THE MIDLINE DIVIDING THE CELL INTO TWO NEW CELLS. CONTROL OF CELL DIVISION CELL GROWTH (G1) CHECKPOINT: PROTEINS TELL THE CELL TO EITHER GO TO THE S PHASE TO COPY DNA OR TO NOT DO THIS BECAUSE CONDITIONS ARE NOT SUITABLE. SOME CELLS GO TO THE G0 PHASE AND DO NOT DIVIDE. DNA SYNTHISIS (G2) CHECKPOINT: DNA REPAIR ENZYMES CHECK THE COPIED DNA. IF ALRIGHT, MITOSIS BEGINS. MITOSIS CHECKPOINT: PROTEINS TELL THE CELL TO EXIT MITOSIS AND GO THE G1 PHASE AGAIN. CANCER PROTEINS ARE PRODUCED BY GENES. IF GENES ARE MUTATED IN A HARMFUL WAY, MALFUNCTIONING PROTEINS DO NOT REGULATE THE CELL GROWTH AND DIVISION. OUT OF CONTROL CELL GROWTH AND DIVISION IS CANCER. MEIOSIS HAPLOID GAMETES (SPERM & EGG CELLS) FORM. SPERM CELL (23 CHROMOSOMES) + EGG CELL (23 CHROMOSOMES) = HUMAN ZYGOTE (46 CHROMOSOMES)- THIS IS SEXUAL REPRODUCTION MEIOSIS I PROPHASE I: CHROMOSOMES FORM TETRADS, PAIRS OF HOMOLOGOUS CHROMOSOMES, PAIR UP IN SYNAPSIS. CROSSING OVER OCCURS WHICH CAUSES GENETIC RECOMBINATION. GENETIC VARIATION MAY LEAD TO ENVIRONMENTAL ADAPTATION. METAPHASE I: TETRADS (HOMOLOGOUS PAIRS OF CHROMOSOMES) LINE UP ALONG THE MIDLINE OF THE CELL IN A RANDOM ORDER CALLED INDEPENDENT ASSORTMENT . THIS GIVES GENETIC VARIATION. ANAPHASE I: HOMOLOGOUS CHROMOSOMES, EACH WITH A PAIR OF CHROMATIDS, MOVE TO OPPOSITE POLES OF THE CELL. TELOPHASE I & CYTOKINESIS: CHROMOSOMES ARE AT THE OPPOSITE POLES OF THE CELL. CYTOKINESIS SPLITS ONE CELL INTO TWO HAPLOID CELLS. MEIOSIS II SPLITS TWO HAPLOID CELLS INTO 4 HAPLOID CELLS GAMETE DEVELOPMENT SPERMATOGENESIS: SPERM (SPERMATOZOA) FORMATION IN THE TESTES. OOGENESIS: EGG (OVUM) FORMATION IN THE OVARIES. THE THREE POLAR BODIES DIE. CELL REPRODUCTION TEST: CHAPTER 4 88 TOTAL POINTS Part I. Multiple Choice. 34 questions @ 2 points each- Directly from notes Part II. Essays Questions. 10 points each/Complete sentences 1. Compare two similarities between mitosis and meiosis. 2. Contrast two differences between mitosis and meiosis. .
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