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BIOS 135 Unit 3
1. Mitosis:
Answer division of the nuclus; prophase, metaphase, anaphase, telophase and cytokinesis
2. Cytokinesis:
Answer division of the cytoplasm to form two separate daughter cells; different in plant and animal cells
3. Sister chromatids:
Answer Identical copies of a chromosome; full sets of these are created during the *S subphase* of interphase.
4. Centromere:
Answer the region of the chromosome that holds the two sister chromatids together
5. Genome:
Answer All the genetic information in an organism; all of an organism's chromo- somes.
6. Interphase:
Answer The cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases
7. G1:
Answer first gap; cell growth and doing its job
8. S phase:
Answer The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. 1 / 3
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9. G2:
Answer Final preparation phase. Cell checks for DNA errors and begins to form centrosomes; prepares for mitosis
10. G0:
Answer a separate phase for cells that do not divide; doing its cell job; may be temporary or permanent
11. Prophase:
Answer Chromosomes become visable and condense, nuclear envelop dis- solves, spindle forms, centrosomes begin to migrate to poles
12. Aster:
Answer A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis.
13. Kinetochore:
Answer A specialized region on the centromere made of proteins that link each sister chromatid to the mitotic spindle.
14. Prometaphase:
Answer Second stage of mitosis, in which the nuclear envelope frag- ments and the spindle microtubules attach to the kinetochores of the chromosomes, chromosomes continue to condense
15. Metaphase:
Answer the phase of mitosis in which the chromosomes line up across the center of the cell at the metaphase plate; the centrosomes are at the poles and kinetochore microtubules are in place
16. Anaphase: 2 / 3
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Answer Phase of mitosis in which the sister chromatids separate and move to opposite ends of the cell; they become a new chromosome; cell elongates due to nonkineticore microtubules
17. Telophase:
Answer phase of mitosis in which the distinct individual chromosomes de- condense, two daughter cells form; nucleoli reappear, spindle microtubules depoly- merize,
18. Animal cell cytokinsesis:
Answer cleavage furrow forms, a contractile ring of microfil- aments pinches the cell into two daughter cells
19. Plant cell cytokinesis:
Answer vesicles from the Golgi move via microtubules to the middle of the cell wall where they join to form a cell plate; the cell plate enlarges until its surrounding membrane fuses with the existing plasma membrane; cell plates secrete all the necessary components of new cell wall
20. Binary fission:
Answer prokaryotes reproduce asexually; do not do mitosis
- chromosome replication begins
- replication continues
- replication finishes
- two daughter cells result
21. Cell cycle control system:
Answer molecules in a cell that triggers and coordinates key events; internal controls, external regulators, checkpoints
22. Checkpoints:
Answer 3 points where regulatory proteins (enzymes) determine if the cell is ready to proceed in the cell cycle; primary checkpoint is G1; the cell will go
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