The DNA fragments show a portion of two nonsister chromatids before crossover. Suppose strand invasion occurs between regions A and B. The heteroduplex extends and forms the Holliday intermediate shown below right. Each dotted line represents one potential plane on which endonucleases could cut the intermediate. DELE a b Left chromatid d A Right chromatid B a Nonsister chromatids before crossover Holliday intermediate Match the chromatids that result from the different ways in which the Holliday intermediate can be resolved. Top chromatid B D Bottom chromatid

Crossing over occurs frequently during prophase 1 Play 0:12 / 1:43 1x CC 目: A tetrad is made up of Multiple Choice two homologous chromosomes, each consisting of two chromatids ) four nonhomologous chromatids four nonhomologous chromosomes four homologous pairs of chromosomes MacBook Air 20 F3 000 F2 F4 F5 F6 F7

There are two different pathways for repairing double-strand breaks in the DNA. In which type of cell is homology-directed repair least likely to be able to repair the damage? Choose one. A haploid cell A diploid cell in G1 phase of the cell cycle A diploid cell in G2 phase of the cell cycle All three the same.

The plant Haplopappus gracilis has a 2n of 4. A diploid cellculture was established and, at premitotic S phase, aradioactive nucleotide was added and was incorporatedinto newly synthesized DNA. The cells were then removed from the radioactivity, washed, and allowed to proceed through mitosis. Radioactive chromosomes or chromatids can be detected by placing photographic emulsionon the cells; radioactive chromosomes or chromatids appeared covered with spots of silver from the emulsion.(The chromosomes “take their own photograph.”) Drawthe chromosomes at prophase and telophase of the firstand second mitotic divisions after the radioactive treatment. If they are radioactive, show it in your diagram. Ifthere are several possibilities, show them, too.

You are studying the M-cyclin. You treat mitotic cells with an inhibitor of the proteasome and find that M-cyclin is no longer degraded and that this prolongs mitosis. You also find that in the presence of the inhibitor, M-cyclin is now running slower/larger in a Western than you have previously observed. In 1-2 sentences, explain why this might be happening. Edit View Insert Format Tools Table 12pt Paragraph B IU Αν S A C I AT²✓ #tv A MacBook Air X : G

Explain why telomerase required in dividing cells but not required in cells that do not divide

Explain two ways that a chromosomal rearrangement can cause a position effect.