Ch 9

  1. genome
    • the complete collection of that organisms' genetic information. This info exists in units called genes that lie along DNA's double helix

  2. DNA

    deoxyribonucleic acid, a long, vanishngly thin molecule.

  3. Chromosomes

    • DNA is devided and packaged into units called chromosomes -= 46 chromosomes
    • Chromosomes are made of chromatin
    • Chromotin - Molecular complex, composed of DNA and associated proteins, that makes up the chromosome.

  4. Sister Chromatids

    • A duplicated chromosomes consists of two sister chromatids that are genetically identical
    • When a cell is not dividing, the chromatin (DNA and associated proteins) is in uncondensed form
    • At the time of cell division, the chromatin condenses into chromosomes

  5. Homologous chromosomes

    • Same in size and function
    • 23 pairs of homologous chromosomes
    • ex. chrom 1 inherit form our mother, and it contains a set of genes very similar characterists to those that lie on chrom 1 from our father.

  6. X and Y chromosomes

    • Females have 23 pairs of homologous chrom, 22 autosomes, and 1 pair of homologus X sex chromosoems.
    • Males have 22 pair of homologues autosomes, and 1 X chromosome and 1 Y chrom.

  7. Mitosis

    is the separation of a cell's duplicated chromosomes prior to cytokinesis.

    4 phases: prophase, metaphase, anaphase, and telophase

  8. Cell cycle

    the repeating pattern of growht, genetic duplication, and divison seen in most cfells.

    2 Phases: Interphase(DNA replication but not yet condensed into chromosomes) and Mitotic phase ( mitosis and cytokinesis)

  9. Prophase

    Chromatin has condensd into chromosomes

    Chromosomes are in duplicated form

    Nuclear envelope is starting to break up

  10. Metaphase

    centrosomes - outside the nucleus, structure that that organizes the assembly of microtubules. As centrosomes move to the cellular poles they are sprouting microtubules that are forming a globe inside the cell stretching it out plus attaching microtubules to sister chromatids (forming mitotic spindle ) and alinging tham at the metaphase plante

  11. Anaphase

    The sister chromatids are pulled apart and moved toward opposite poles of the cell

    Each chromatid is now a full-fledged chromosome

  12. Telophase

    The chromosomes unwind.

    Nuclear envelope form

    Mitotic spindle disapear

    Two daughter nuclei are present in one elongating cell

  13. Cytokinesis

    A controctile ring of protein filaments forms a cleavage furrow at teh euqator of the cell

    The ring contracts until the parent cell is pinched in two

  14. How DNA packaged within cells?

    duplicated DNA is wraped around an associated protein making a chromatin that condences into a chromosome.

  15. When does cell division occur?

    during grows, replace lost or damaged cells, repair injuries

  16. During which phase of the cell cycle is DNA replicated?


  17. During which phase of mitosis does DNA condense into chromosomes?


  18. What role do microtubles play in cell division?

    Pulling sister chromatids apart
Card Set
Ch 9