What type of mutation causes down syndrome? (point, frameshift, deletion, insertion, etc.) -- Why is it categorized as this type of mutation?​

Trisomy 21: About 95% of people with Down syndrome have Trisomy 21. With this type of Down syndrome, each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies. Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3%).

cdc

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

not only is it colder, it also becomes darker, less salty, and more dense.