Question

60. (1) Human genetic diseases such a Cri-du-chat, Angelman syndrome and Prader-Willi syndrome are the result of which of the following?


Translocations

Duplications

Deficiencies

Inversions

Answer 1

All three of these illnesses come from DNA deletions. So (c) is your answer.

Prader-Willi and Angelman are on chromosome 15. PWS develops if the paternal chromosome has deletions or misses entirely. In some cases, the maternal chromosome is doubled in the F1, this causes PWS.
This also goes for Angelman. The only difference: Parts of the maternal chromosome are deleted or the paternal chromosome is doubled.

Why do I say that? Because one could think of duplication as the right answer - but since cri du chat is only caused by deficiencies, (c) is right.