Answer the following question given this paragraph: 

A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes.


Q: What is a mutation that changes all or much of a particular chromosome?


A:
chromosomal mutation