11.3 Flashcards
Describe the 4 distinct features of meiosis
Homologous pairing & crossing over
Sister chromatids remain joined @ their centromeres & segregate together during anaphase I
Kinetochores of sister chromatids attach to the same pole in meiosis I
DNA replication is suppressed between meiosis I & II
Illustrate the difference between chromosome behavior in mitosis
Homologues do NOT pair
microtubules attach to kinetochores on each sister chromatid
microtubules pull sister chromatids apart
Illustrate the difference between chromosome behavior in meiosis I
Crossovers & sister chromatid cohesion lock homologues together
Microtubules connect to the kinetochores of an entire homolog so that homologues are pulled toward opposite poles
Microtubules pull the homologous chromosomes apart, but sister chromatids are held together at the centromere
Describe the differences in chromatid cohesion in meiosis and mitosis.
Meiosis-specific cohesion proteins
Maintenance of sister chromatid cohesion @ centromere during all of meiosis I
Explain the importance of the suppression of replication between meiotic divisions.
o gametes would be diploid, and zygotes would be tetraploid
o Cyclin B is important in suppressing replication
Explain how the cells resulting from meiosis are not identical.
Not identical cells are due to random orientation of chromosomes @ meiosis I & because of crossing over