Meiosis creates new life from old cells. It occurs exclusively in reproductive cells, and is the form of cell division that produces eggs and sperm.

Meiosis has two goals: creating daughter cells that have only half the number of chromosomes as the parent cell, and creating daughter cells with unique genetic information.

Interphase
The cell cycle that describes the life of cells separates cell division from interphase. But the stage between cell divisions is vital to the process because the chromosomes that will be reshuffled and divided in meiosis are duplicated in interphase.

During the stages of interphase, reproductive cells grow and prepare for meiosis. The chromosomes are duplicated and the copies are checked for accuracy and completeness. Parts of the spindle apparatus that will split and distribute the chromosomes are also replicated.

The preparations for meiosis that occur during interphase are largely invisible even under microscopic magnification. The duplicating chromosomes and centrosomes are invisible within the nucleus and cytoplasm.

Chromosome Terminology
A normal cell has two copies of each chromosome—one copy inherited from the mother, the other copy inherited from the father. Together these two chromosomes form a matched but not identical pair, called homologous chromosomes. A cell in this condition is said to be diploid.

This is often abbreviated as 2n, which is a reference to n pairs of chromosomes. For example, humans have 23 pairs of chromosomes, or a total of 46 chromosomes altogether.

In a cell in G1 or G0 going about its normal metabolic processes, each of the chromosomes consists of a single strand of DNA. After the cells commit to cell division, the chromosomes replicate in the S stage of interphase. Then each individual chromosome is made up of two identical strands of DNA, called sister chromatids, which are attached to one another at a single point known as the centromere.