Meiosis is used to to make sex cells.
Mitosis is used to make regular cells for you body.
Because many living organisms begin in the womb similarly, showing that organisms have a common ancestor
The Prader-Willi syndrome (PWS) is due to the lack of expression of paternal genes of the 15q11-q13 region. It usually occurs sporadically, although some family cases have been described (<1%). Approximately 70% of cases are produced by deletions of paternal origin in the 15q11-q13 region. 28% of cases are due to maternal uniparental disomy and less than 2% are caused by imprinting alterations. A geneticist studying prader-willi syndrome should focus on chromosome 15, its structure or changes in the number, these anomalies are also related to other syndromes such as: Bloom Syndrome, Breast cancer, Isovaleric acidity among others.