Which of the following features characterizes apoptosis but not necrosis?
Apoptosis is a form of cell death that serves to eliminate unwanted cells during development, maintain cell numbers in intact organs or tissues, and eliminate immune cells after an immune response has faded. Apoptosis also occurs in response to noxious agents and in the aging process. The process is the result of execution of an internal program mediated by the expression of a number of different genes. In the process of apoptosis, cells shrink and cytoplasmic organelles become more densely packed. Cytoplasmic blebs may form, and apoptotic bodies (membrane-bound cellular fragments) can be produced. The most characteristic feature of apoptosis is a distinctive peripheral aggregation of chromatin, sometimes accompanied by breaking up of the nucleus into several fragments. In necrosis, the chromatin may become more pale (karyolysis), or form irregular clumps, and the nucleus itself may shrink into a dense pyknotic body. Disaggregation of polyribosomes is characteristic of the initial stages of cellular injury and necrosis. Eosinophilia characterizes both apoptosis and necrosis. Inflammation is typically absent in apoptosis, in contrast to necrosis. Ref: Jan B.V., Lowry S.F. (2010). Chapter 2. Systemic Response to Injury and Metabolic Suppo. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwaz's Principles of Surgery, 9e.
Disaggregation of polyribosomes
Eosinophilia
Inflammation
Peripheral aggregation of chromatin