2024 Karp Cell & Molecular Bio Chapter 14 Questions With Answers

Cell cycle - ANSWER- the series of stages a cell goes through M Phase - ANSWER- includes the process of mitosis and cytokinesis interphase - ANSWER- the majority of the cell cycle and lasts longer than the M phase; it may extend for days, week, or longer. G1 - ANSWER- takes place between the end of mitosis and the beginning of DNA replication. S phase - ANSWER- DNA replication occurs during this phase of the cell cycle G2 - ANSWER- occurs between the end of S and the beginning of mitosis asymmetric division - ANSWER- daughter cells have different fates than parent cell quiescent - ANSWER- a dormant cell senescent - ANSWER- an aging or deteriorating cell Maturation promoting factor - ANSWER- consists of two subunits: a kinase and a regulatory subunit, cyclin. cyclin dependent kinases - ANSWER- The kinase is always present, Production of the cyclin leads to activation of the kinase cdc2 - ANSWER- a kinase that is needed to start both commitment points; activity is regulated by different cyclins Wee1 - ANSWER- promotes early cell division, thus smaller cells cdc25 - ANSWER- prevents cell division, but allows cell to keep growing. Also called string CDK inhibitor - ANSWER- proteins that prevent cyclin dependent kinases from functioning controlled proteolysis - ANSWER- mitotic cyclins are targeted and destroyed by ubiquitin ligases so that the cell can exit mitosis and enter a new cell cycle cell cycle checkpoint - ANSWER- surveillance mechanisms that stop the cell cycle if there is any damage to DNA or if critical processes like DNA replication or mitosis are not completed mitosis - ANSWER- a process of nuclear division in which two nuclei with identical genetic content are produced prophase - ANSWER- duplicated chromosomes are prepared for segregation and the mitotic machinery is assembled chromosome compaction - ANSWER- occurs in early prophase producing the characteristic mitotic chromosome topoisomerase II - ANSWER- twists the chromatin in a super-coiled structure cohesin - ANSWER- holds the compacted sister chromatids together condensin - ANSWER- (a G2/M cyclin-Cdk target) helps compact intramolecular DNA. centromere - ANSWER- occurs at a primary constriction on chromosomes and serve as the binding site for numerous proteins kinetochore - ANSWER- outer surface of centromere; sites where chromosomes attach to the microtubules of the mitotic spindle centrosome - ANSWER- a microtubule organizing center mitotic spindle - ANSWER- microtubules that run from the centrosome to the kinetochore prometaphase - ANSWER- definitive mitotic spindle is formed and chromosomes are moved by microtubules to the center of the cell differential growth - ANSWER- this process centers chromosomes at the center of the spindle metaphase - ANSWER- chromosomes align at the spindle equator on the metaphase plate anaphase - ANSWER- begins when sister chromatids split and move apart anaphase promoting complex - ANSWER- ubiquinates a key anaphase inhibitor, causing securin - ANSWER- an anaphase inhibitor located on the kinetochore anaphase A - ANSWER- movement of chromosomes towards the poles during mitosis anaphase B - ANSWER- spindle poles move in opposite directions due to elongation of polar microtubules and plus end directed kinesin activity ndc80 - ANSWER- protein complex that links the kinetochore to the depolymerizing microtubule spindle checkpoint - ANSWER- operates at metaphase/anaphase transition; unattached kinetochores send a "wait" signal to prevent entry to anaphase aneuploidy - ANSWER- daughter cells that receive an abnormal number of chromosomes telophase - ANSWER- final stage of mitosis; daughter cells return to interphase cytokinesis - ANSWER- cytoplasm is partitioned into two cells contractile ring theory - ANSWER- a thin band of actin and myosin filaments generate the force to cleave a cell meiosis - ANSWER- cell reproduction in which chromosome number is halved and four haploid daughter cells are formed spermatagonia - ANSWER- male gamete that can commit to meiosis and become a primary spermatocyte oogonia - ANSWER- female gamete that can enter meiosis and become a primary oocyte polar body - ANSWER- cast out of the primary oocyte after meiosis I and another is generated after meiosis II synapsis - ANSWER- homologous chromosomes pair associated via the synaptonemal complex tetrad - ANSWER- synapsed chromosomes form this chiasmata - ANSWER- remaining attachment points between homologous chromosomes diakinesis - ANSWER- chromosomes are prepared for attachment to spindle fibers Metaphase I - ANSWER- two homologous chromosomes are aligned at the metaphase plate, held to gether by chiasmata