Mitosis

Misc. facts

occurs in somatic cells; does not involve gametes (which occurs in meiosis)

Interphase

Functions in growth, DNA replication, and cell functions

90% of the cell cycle is interphase, 10% is mitosis

Mitosis Pathway

Metaphase

Prophase

Anaphase

Telophase

Nucleus present but degrades

Chromatin condenses into chromosomes and sister chromatids form

Chromosomes line up in middle of cell

Sister chromatids are separated via spindles of centrioles

Chromatids are on separate ends

Two new nuclei form

Cytokinesis

Cytoplasm is split

Chromosomes

46 chromosomes

Cells (somatic) with two sets of chromosomes are diploid

Cells (gametes) with one set of chromosomes are haploid

DNA is chromatin at this point

In preparation for prophase, centrioles duplicate and DNA replicates to give two copies of DNA

Microtubules begin extending from centrioles

This occurs via motor proteins (one of either side of the centromere) called centromere associated protein e

Motor proteins attach to microtubules

Dynein tightens the microtubule slack by bouncing back from side to side and tightening the microtubules until the chromosomes are in the middle

Chromosomes relax back into chromotin

Cleavage begins

The first step of interphase is G1 (gap 1), where the cell grows

Next is S (synthesis) phase, where DNA is copied

IN G2, the cells grow again

Cells in G0 phase (such as nerves and muscles) do not copy themselves

The spindle attaches to the kinetochore

Prometaphase

Microtubules attach to kinetochores

Checkpoints

Occurs at G1, S, end of G2, and M phases

The checkpoints occur through cyclin and protein kinases via phosphorylation cascade

Phosphorylation is adding a phosphate group to another molecule

Some kinases must be bound to a cyclin to be activated (CDK)