Cell injury- Atrophy mechanism

When a fractured bone is immobilized in a plaster cast or when a patient is restricted to complete bed rest, skeletal muscle atrophy rapidly ensues. The primary mechanism of atrophy involves which of the following?

Cell injury- step ladder PICTURE

Newer drugs are being tested for their capacity to induce cancer cell death. Agarose gel electrophoresis pattern from DNA of a population of cells is shown below. What is the correct explanation for the finding is seen in the band labeled as “M”?