1 Do cells enter meiosin before after during S phase? 2 What are the similarities and differences of reduction and equational division? Solution 1. The S phase of cell cycle occur during interphase before mitosis or meiosis ,in this phase synthesis of DNA takes place. 2.Major difference are : Reductional meiosis is also known as first meiotic division in which diploid divides into two daughter cell which is monoploid this due to separation of whole chromosome. In equational division separation of chromatics occur per chromosome so there is no change is chromosome number..