In which phases of mitosis and meiosis are the principles of segregation and independent assortment at work?

1-Meiosis:  

- Independent assortment: Anaphase I

- Segregation: Anaphase II

2-Mitosis  

- Segregation: Anaphase  

Explanation:

The Principle of Independent Assortment described by Mendel indicates the mechanism by which different genes get sorted into gametes (i.e., eggs and sperms in mammals) independently of one another, while the Principle of Segregation indicates the mechanism by which gene variants (i.e., alleles) segregate (separate) into gamete cells. In eukaryotic organisms, independent assortment occurs during anaphase I of meiosis, when each pair of homologous chromosomes separate. The assortment of homologous chromosomes during anaphase I explain how genes on different chromosome pairs will segregate independently of one another. On the other hand, the separation (segregation) of sister chromatids occurs in Anaphase II, where gametes carrying single gene variants (i.e., alleles) for each locus are generated.