Distinguish anaphase of mitosis from anaphase I of meiosis.
Anaphase of Mitosis:
In anaphase of mitosis, the centromere of each chromosome splits, allowing the sister chromatids to separate and move toward opposite poles of the cell. The sister chromatids become individual chromosomes.
Anaphase I of Meiosis:
In anaphase I of meiosis, the homologous chromosomes separate and move to opposite poles, while the sister chromatids remain associated at their centromeres. Each pole receives half the chromosome number of the parent cell.
Key Difference:
The fundamental distinction is that in mitotic anaphase, sister chromatids separate, whereas in anaphase I of meiosis, homologous chromosomes separate with sister chromatids remaining attached together.
Explanation
The textbook clearly distinguishes these two phases. In anaphase I of meiosis, homologous chromosomes separate while sister chromatids stay together at their centromeres. In contrast, meiosis II (which resembles mitosis) involves the separation of sister chromatids during anaphase II, where centromeres split. This distinction is crucial for understanding how meiosis reduces chromosome number by half while mitosis maintains it.