mitosis

Cell Division

The process by which a parent cell divides into two daughter cells.

Cell Cycle

A larger process in which a cell grows, replicates its chromosomes, and then divides.

Mitosis

begins after DNA has been replicated (during interphase); it consists of four stages— prophase, metaphase, anaphase, and telophase; the result is two daughter nuclei, each identical to the mother nucleus. A vegetative division that produces daughter cells genetically identical to the parent cell. (nuclear division)

Meiosis

A type of cell division that produces haploid gametes for sexual reproduction, reducing chromosome number from diploid (two of each type) to haploid (one of each type).

S Stage of Interphase

The phase in which DNA replication occurs before mitosis.

M Phase

The phase of the animal cell cycle that includes all stages of mitosis and results in the division of a mother cell into two genetically identical daughter cells.

Telophase

The final stage of mitosis where the two new nuclei form.

DNA Checkpoints

Control mechanisms in the cell cycle that detect and repair DNA damage, halting the cycle if necessary by inhibiting certain cyclin-CDK complexes.

First Division of Meiosis

Homologous chromosomes are separated, so each daughter cell receives one copy of each chromosome.

Second Division of Meiosis

The sister chromatids of the replicated chromosomes are separated into different daughter cells.

Sexual Reproduction

A process involving both mitosis and meiosis at different stages of the life cycle.

Last Eukaryotic Common Ancestor

The ancestral organism in which both mitosis and meiosis are believed to have first evolved.

Mitotic cell division

provides an increased number of cells for growth and repair.

Interphase

The cell's preparation phase before division, consisting of G1 (growth), S (DNA replication), and G2 (final preparations for division). Checkpoints ensure proper cell size, DNA integrity, and chromosome attachment. Controlled by cyclins and cyclin-dependent kinases.

G1 Phase

Cell grows and prepares for DNA replication.

S Phase

DNA is replicated to maintain genetic content.

G2 Phase

Final growth and spindle synthesis before division.

Prophase

First stage of division. Chromatin condenses into chromosomes, nuclear envelope breaks down, spindle fibers form. In meiosis, crossing over occurs.

Prometaphase

Nuclear envelope fully breaks down, spindle fibers attach to chromosomes at kinetochores.

Metaphase

Chromosomes align at the center (metaphase plate), spindle fibers fully attached.

Anaphase

Sister chromatids separate and move to opposite poles, pulled by spindle fibers.

Telophase

Nuclear envelopes reform around separated chromosomes, chromatin loosens, and nucleolus reappears.

Cytokinesis

Final division of the cytoplasm, forming two daughter cells. In animals, a contractile ring forms; in plants, a cell plate develops into a cell wall. usually begins during anaphase and progressively pinches the cytoplasm in half. (division of the cytoplasm)