Cell Division: Mitosis and Meiosis Overview

Eukaryotic Cell Cycle

Life cycle of a typical eukaryotic cell.

Mitosis

Process producing two genetically identical daughter cells.

Meiosis

Process producing four genetically diverse gametes.

Interphase

Preparation phase for cell division.

G1 Phase

Cell growth and organelle replication.

S Phase

DNA synthesis occurs, producing identical copies.

G2 Phase

Final preparations for mitosis, checks DNA synthesis.

Mitotic Phase

Division of the nucleus and cytoplasm.

Prophase

Chromatin condenses into chromosomes, spindle forms.

Metaphase

Chromosomes align at the metaphase plate.

Anaphase

Sister chromatids are pulled apart to poles.

Telophase

Chromosomes revert to chromatin, nuclear envelopes reform.

Cytokinesis

Division of cytoplasm, forming two complete cells.

Checkpoints

Regulatory points ensuring proper cell cycle progression.

G1 to S Checkpoint

Decides if the cell should divide.

G2 to M Checkpoint

Checks readiness to enter mitosis.

CDK

Cyclin-dependent kinase, regulates cell cycle progression.

Cyclin

Binds to CDK, activating it for mitosis.

MPF

Mitotic Promotion Factor, initiates mitosis.

Colchicine

Inhibits mitosis by blocking microtubule formation.

Meiosis I

Homologous chromosomes are separated.

Prophase I

Chromosomes condense, homologous pairing and crossing over.

Metaphase I

Homologous chromosomes align at the equator.

Anaphase I

Homologous chromosomes pulled to opposite ends.

Telophase I

Two new cells form with one chromosome each.

Meiosis II

Similar to mitosis, separates sister chromatids.

Genetic Variation

Occurs in meiosis through crossing over.

Diploid Cells

Cells with two sets of chromosomes (2n).

Haploid Cells

Cells with one set of chromosomes (1n).