During mitotic and meiotic cell division, chromosomes are usually duplicated, and chromosome pairs are separated, so each daughter cell has a copy of each chromosome.
Translocation Down Syndrome:
This condition occurs when a portion of chromosome 21 is transferred to another chromosome (usually chromosome 14).
It does not result in an extra copy of chromosome 21, but rather some of the long arms of chromosome 21 as part of chromosome 14.
Down syndrome symptoms may be absent in the parent but can be passed on to the child.