Which of the following is the initial observable event in the apoptotic process?

• A. Cell fragments are consumed by white blood cells
• B. Cell rounds and nucleus collapses
• C. Chromatin condenses and nucleus fragments
• D. Plasma membrane blisters and blebs form

Answer: (B)

Apoptosis starts with the cell shrinking and changing shape as the cytoskeleton breaks down, so the first visible changes are when the cell rounds up. At the same time, the nucleus begins to show early changes—chromatin condenses and the nucleus may begin to fragment—so you can notice a nucleus that looks collapsed or altered early on. These initial morphological changes set the stage for later events like membrane blebbing, formation of apoptotic bodies, and eventual phagocytosis. Therefore, the earliest observable signs are the cell rounding together with initial nuclear changes, which is why this option best fits the initial event in apoptosis.