BIOL 2520 Lecture Notes - Lecture 4: Multinucleate, Ubiquitin, Cleavage Furrow

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2520
• Professor: Dr.W

Document Summary

Prophase: nuclear envelope disappears; chromosomes condense, duplicated chromosomes each consisting of two closely associated sister chromatids, condense. Outside the nucleus, the mitotic spindle assembles between the two centrosomes, which have begun to move apart. Prometaphase: mitotic spindle forms; chromosomes attach to spindle, starts abruptly with the breakdown of the nuclear envelope. Chromosomes can now attach to spindle microtubules via their kinetochores and undergo active movement. Metaphase: chromosomes aligned along equator, chromosomes are aligned at the equator of the spindle, midway between the spindle poles. The kinetochore microtubules on each sister chromatic attach to opposite poles of the spindle. Anaphase: chromatids separate; chromosomes migrate to poles, sister chromatids synchronously separate and are pulled slowly toward the spindle pole to which they are attached. The kinetochore microtubules get shorter, and the spindle poles also move apart, both contributing to chromosome segregation. Telophase: chromosomes decondense; nuclear envelope forms, the two sets of chromosomes arrive at the poles of the spindle.