BIO1011 Lecture Notes - Lecture 6: Chromatin, Homologous Chromosome, Nuclear Membrane
6 Jun 2018
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Stages of Mitosis
Prophase
➢ First and longest phase of mitosis.
➢ Chromosomes become visible. Centrioles separate and take positions on
opposite sides of the nucleus.
➢ Chromosomes become attached to fibers in the spindle at a point near
the centromere of each chromatid.
Metaphase
➢ Second phase of mitosis.
➢ Chromosomes line up across center of cell.
➢ Centromere of each chromosome connect to the two poles of the spindle.
Anaphase
➢ Third phase of mitosis.
➢ Centromeres that join the "sister" chromatids split and the chromatids
separate and become individual chromosomes.
➢ They move until in two groups near the poles of the spindle.
Telephase
➢ Fourth and final phase of mitosis.
➢ Chromosomes, which were distinct and condensed, disperse into a tangle
of dense material.
➢ Nuclear envelope reforms around each cluster of chromosomes.
Cytokinesis
Division of the cytoplasm after nucleus has divided. Occurs after telophase.
G1 part of
interphase
Growth and development
S phase of
interphase
DNA replication occurs, makes two sets of DNA
G2 phase of
interphase
Duplication of all organelles and final preparation for mitosis.
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Document Summary
Centrioles separate and take positions on opposite sides of the nucleus. Chromosomes become attached to fibers in the spindle at a point near the centromere of each chromatid. Chromosomes line up across center of cell. Centromere of each chromosome connect to the two poles of the spindle. Centromeres that join the sister chromatids split and the chromatids separate and become individual chromosomes. They move until in two groups near the poles of the spindle. Chromosomes, which were distinct and condensed, disperse into a tangle of dense material. Nuclear envelope reforms around each cluster of chromosomes. Division of the cytoplasm after nucleus has divided. Dna replication occurs, makes two sets of dna. Duplication of all organelles and final preparation for mitosis. interphase. At this point the dna is in its chromatin form. The dna starts to coil itself up into visible chromosomes. The copies of each chromosome (sister chromatids) are connected together by a centromere.
