Definition: A daughter chromosome is a chromosome that results from the separation of sister chromatids during cell division. Daughter chromosomes originate from a single stranded chromosome that replicates during the synthesis phase (S phase) of the cell cycle. The duplicated chromosome becomes a double-stranded chromosome and each strand is called a chromatid. Paired chromatids are held together at a region of the chromosome called the centromere. The paired chromatids or sister chromatids eventually separate and become known as daughter chromosomes. At the end of mitosis, daughter chromosomes are properly distributed between two daughter cells.
Daughter Chromosome: Mitosis
Prior to the start of mitosis, a dividing cell goes through a period of growth called interphase in which it increases in mass and synthesizes DNA and organelles. Chromosomes are replicated and sister chromatids are formed.
- Prophase – sister chromatids begin migrating to the center of the cell.
- Metaphase – sister chromatids align along the metaphase plate.
- Anaphase – spindle fibers separate sister chromatids by pulling them centromere first toward opposite ends of the cell. Once separated, each chromatid becomes known as a daughter chromosome.
- Telophase – daughter chromosomes are separated into distinct new nuclei.
After cytokinesis, two distinct daughter cells are formed from a single cell. Daughter chromosomes are equally distributed between the two daughter cells.
Daughter Chromosome: Meiosis
Daughter chromosome development in meiosis is similar to mitosis. In meiosis however, the cell divides twice producing four daughter cells. Sister chromatids do not separate to form daughter chromosomes until the second time through anaphase or in anaphase II. The cells produced in meiosis contain half the number of chromosomes as the original cell. Sex cells are produced in this manner. These cells are haploid and upon fertilization are united to form a diploid cell.