The mitotic phase proceeds through four main stages, followed by cytokinesis. During prophase, DNA condenses into chromosomes, with sister chromatids joined at the centromere while spindle fibers form. Metaphase aligns these chromosomes at the cell's center. Anaphase pulls the separated chromatids to opposite poles, and telophase sees the chromosomes uncoiling as new nuclear envelopes form.

Definition: Cytokinesis is the physical division of the cell's cytoplasm into two daughter cells.

Vocabulary: Centromeres are the connection points between sister chromatids, while spindle fibers are the protein structures that pull chromosomes apart.

Highlight: Cytokinesis begins during late anaphase or early telophase, ensuring proper separation of cellular components.

Example: The process of cytokinesis can be visualized as a drawstring purse being pulled tight in the middle of the cell.

The first phase of cell division begins with interphase, which consists of three distinct stages. During G₁, the cell undergoes growth and normal metabolic activities. In the S phase, DNA replication occurs, while G₂ prepares the cell for division.

Definition: Interphase is the period between cell divisions where the cell grows and replicates its DNA.

Vocabulary: Chromatin refers to loosely packed DNA during interphase, while chromosomes are the tightly packed form visible during mitosis.

Highlight: The G₁ checkpoint is crucial as it determines appropriate growth conditions and assesses DNA damage levels.

Example: Think of chromatin as relaxed strings that later condense into visible chromosomes during division.