The Science of Existence (125-1) Life Cycle

Life Cycle

The contents of chromatin and its chromosomes undergo structural changes during the cell cycle.

Interphase is the 90% of a cell’s life cycle when it lives its everyday life: eating, producing bioproducts, doing cellular business, and growing. Interphase also includes preparation for cell division.

During interphase, nucleosomes with active genes are more loosely packaged than inactive genes. In preparing to divide, during prophase, chromatin packages tighten up. The nucleolus disappears. DNA has already been replicated prior to prophase.

Chromatin compaction is a dynamic process, full of decisions which can foreclose access to the genetic codes within, thus thwarting transcription. This suppression happens via epigenetic regulation.

Metaphase is the stage of cell division where chromosomes migrate to opposite poles of a cell. During anaphase, 2 identical daughter chromosomes form.

Next comes telophase, which starts with 2 daughter nuclei forming. Cytokinesis follows, with the cytoplasm bifurcated. The outcome of telophase is 2 daughter cells, each with a selfsame set of chromosomes.