Solution:
The four types of chromosomal structural abnormalities can be grouped into the following two groups:
Balanced structural anomalies:
1. Translocations: simple or complex movement of chromosome fragments or whole chromosomes. Chromosome breaks and a part of it is attached to a different chromosome.
2. Inversion: where the chromosomal region is flipped so that it points in the opposite direction. That is, part of a chromosome breaks off at two points and the segment in between turns upside down and then rejoins the same chromosome.
Unbalanced structural anomalies:
3. Duplication: where part of a chromosome is copied. This means that a part of the chromosome is duplicated or has two copies. The result is additional chromosomal material.
4. Deletion: where part of a chromosome is removed. That is, there is DNA loss.