Genome Structure part 2

  1. 4 phases are considered for a complete cell cycle:
    • G1, S, G2, M
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  2. phases where the cells are not actively dividing
    G1/G0
  3. In G0, cells are __
    not engaged in cell division and are not going to divide
  4. In G1, __
    DNA is deciding to replicate
  5. DNA replication occurs in the __ phase. During this phase, __
    • S; duplicated DNA become sister chromatids attached to each other by cohesin and also attached at the centromere
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  6. In the G2 phase, cells __
    prepare for mitosis (chromosome segregation)
  7. interphase
    • Cell is not visibly (by microscope) in the process of dividing but DNA replication (S phase) occurs
    • includes G1, S, and G2
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  8. steps of the M phase
    • Prophase: Spindles form, chromatin gets condensed
    • Metaphase: Chromosomes line up in the center of the cell.
    • Anaphase: Sister chromatids separate.
    • Telophase: Chromatin gets less condensed, spindles disappear, 2 daughter cells start splitting
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  9. structures at the end of linear chromosomes
    telomere
  10. Telomeric DNA is made up of a few type of __ sequence
    • minisatellite (a few hundred copies
    • of a short repeat motif, 5`TTAGGG–3' at each end of every chromosome.)
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  11. Part of the DNA at the end of the telomere is __
    single stranded
  12. Proteins are attached to the telomere to __
    • Protect the end of the chromosome from degradation and nucleotide deletion
    • Distinguishing the end of the chromosome from a break in the double strand
  13. Extension of telomeres is done by __ that uses __ as the template
    • telomerase;
    • RNA
  14. occurs during M phase
    • chromosome condensation
    • attachment of spindles (microtubules) to the kinetochores
    • segregation of the chromosomes after digestion of cohesins
    • pulling chromosomes to the sides of the cells
  15. Chromosomes are far less compact when a cell is __ and they are seen in the __ format.
    • not in the process of cell division (interphase);
    • chromatin
  16. After DNA replication in S phase, chromosomes become more and more __ before going for cell division. The most compact form of the chromosome is in the __ phase.
    • compact; M
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  17. Sister chromatids are kept attached to each other by __
    cohesins
  18. cohesin
    • 2 large structural maintenance of chromosome proteins (SMC) with 2 non-SMC protein to form a ring (around the 2 sister chromatids)
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  19. Digestion of non-SMC causes __
    opening of the ring and separation of chromatids
  20. How does chromosome condensation happen?
    Condensin (ring shaped SMC containing protein complexes) possibly cause condensation by linking different parts of a chromosome together
Author
sophathida
ID
328211
Card Set
Genome Structure part 2
Description
Week 4
Updated