BIOL 150 Lecture Notes - Lecture 26: Ploidy, Oocyte, Kinetochore
Document Summary
Biol 150 principles of molecular & cellular biology. The secret lies in the kinetochore attached to the plus end of the microtubules. Once the microtubule plus end has grown far enough for the kinetochore to attach to the centromere, the kinetochore then directs the plus end to depolymerize slowly (not rapidly as in catastrophe). The kinetochore catalyzes the removal of tubulin dimers from the plus end, while remaining in contact with the new plus end of the microtubule as well as with the centromere. The microtubule gradually shortens to pull the chromosome towards the center of the cell in metaphase, and then to pull the 2 halves of the chromosome apart in anaphase. Cells contain 2 copies (2n = diploid) of all your genes and chromosomes (except for sex chromosomes in males), one copy from mother and one from father. This means that each parent must donate one copy of chromosomes to make the progeny organism.
