Which type of mutation results in an extra copy of all or part of a chromosome?

Duplication

Explanation:

Mutations can be defined as changes that occur in the genetic material (DNA) of living organisms. These changes are an important source of genetic variability and are often responsible for the emergence of new species.

Mutations are classified into a few different types. In the case of the above question, the mutation is termed as "duplication".

In duplication, there is the formation of an additional segment in one of the chromosomes. In general, the consequences of duplication are well tolerated as there is no shortage of genetic material.