Anaphase - A Cell Biology Definition

Meiosis Anaphase I
Lily Anther Microsporocytes in Anaphase I. Ed Reschke/Photolibrary/Getty Images

What Is Anaphase?

Definition: Anaphase is a stage in mitosis and meiosis where chromosomes begin moving to opposite ends (poles) of a dividing cell.

In the cell cycle, a cell prepares for growth and division by increasing in size, producing more organelles and synthesizing DNA. In mitosis, the DNA is divided evenly among two daughter cells. In meiosis, it is distributed between four haploid cells. Cell division requires a lot of movement within a cell.

Chromosomes are moved by spindle fibers in order to ensure that each cell has the correct number of chromosome after dividing.

Mitosis

Anaphase is the third of four phases in mitosis. The four phases are: Prophase, Metaphase, Anaphase, and Telophase. In prophase, chromosomes migrate toward the cell center. In metaphase, chromosomes align along the center plane of the cell known as the metaphase plate. In anaphase, the duplicated paired chromosomes, known as sister chromatids, separate and begin moving toward opposite poles of the cell. In telophase, chromosomes are segregated into new nuclei as the cell splits, dividing its contents between two cells.

Meiosis

In meiosis, four daughter cells are produced, each with half the number of chromosomes as the original cells. Sex cells are produced by this type of cell division. Meiosis consists of two stages: Meiosis I and Meiosis II. The dividing cell goes through two phases of prophase, metaphase, anaphase, and telophase.

In anaphase I, sister chromatids begin moving toward opposite cell poles. Unlike in mitosis however, the sister chromatids do not separate. At the end of meiosis I, two cells are formed with half the number of chromosomes as the original cell. Each chromosome however, contains two chromatids instead of a single chromatid.

In meiosis II, the two cells divide again. In anaphase II, sister chromatids separate. Each separated chromosome consists of a single chromatid and is considered to be a full chromosome. At the end of meiosis II, four haploid cells are produced.

Related Terms: Mitosis and Meiosis

Pronunciation: an-uh-phase