During anaphase, DNA exists as two identical, independent chromosomes that have been separated from their sister chromatids.
Anaphase Explained
Anaphase is a crucial stage of cell division, both in mitosis (for somatic cells) and meiosis (for germ cells). It's the phase where the duplicated genetic material is divided equally into two daughter cells. The core event is the separation of sister chromatids, which are identical copies of a single chromosome joined at the centromere.
Key Events During Anaphase
- Sister Chromatid Separation: This is the defining event. The centromere divides, and the sister chromatids become individual chromosomes.
- Chromosome Movement: These newly separated chromosomes move towards opposite poles of the cell. This movement is driven by a structure called the mitotic spindle. The reference states: "During anaphase, each pair of chromosomes is separated into two identical, independent chromosomes. The chromosomes are separated by a structure called the mitotic spindle."
Visualizing DNA in Anaphase
Imagine a chromosome as an "X" shape before anaphase. Each half of the "X" is a sister chromatid. During anaphase, this "X" is split in the middle, and each half (now a single chromosome) moves to opposite sides of the cell. Therefore, DNA in anaphase is in the form of these separated, single chromosomes.
Table Summarizing Anaphase
| Feature | Description |
|---|---|
| Key Event | Separation of sister chromatids |
| DNA Form | Two identical, independent chromosomes |
| Movement Mechanism | Mitotic spindle |
| Outcome | Equal distribution of genetic material to daughter cells |
