Chapter 12: Cell Cycle

Diploid (2n)

A diploid cell has two sets of chromosomes, one from each parent. Example: Human body cells are diploid with 46 chromosomes (23 pairs).

Haploid (n or 1n)

A haploid cell has one set of chromosomes. Example: Human gametes (sperm and egg) are haploid with 23 chromosomes.

Interphase

The non-dividing stage of the cell cycle where cell growth and DNA replication occur.

Mitosis

A process used for growth, repair, and asexual reproduction resulting in two daughter cells.

Meiosis

A process that produces haploid gametes (sex cells) from a diploid cell.

G1 Phase (Gap 1)

Phase of interphase where the cell grows, performs normal functions, and makes new organelles.

S Phase (Synthesis)

Phase where DNA replication occurs, resulting in two sister chromatids held together at a centromere.

G2 Phase (Gap 2)

Final preparation phase before division where the cell makes proteins needed for mitosis.

Karyokinesis

The division of the nucleus during mitosis or meiosis.

Cytokinesis

The division of the cytoplasm into two new daughter cells.

G0 Phase

A resting/non-dividing stage where cells exit the cell cycle and differentiate.

Cell Cycle Regulation

Controlled by checkpoints that verify cell size, DNA integrity, and proper chromosome replication.

Time Frame of Interphase

Interphase typically lasts about 20 hours, making up about 90% of the entire cell cycle.

Binary Fission

The method of cell division for prokaryotic cells, involving simple splitting of the cell.

Checkpoint

Control mechanism in the cell cycle that ensures proper progression and prevents uncontrolled division.