According to Darwin, evolution occurs because of natural selection.
Eukaryotic cells have been confronted throughout their evolution with potentially lethal plasma membrane injuries, including those caused by osmotic stress, by infection from bacterial toxins and parasites, and by mechanical and ischemic stress. The wounded cell can survive if a rapid repair response is mounted that restores boundary integrity. Calcium has been identified as the key trigger to activate an effective membrane repair response that utilizes exocytosis and endocytosis to repair a membrane tear, or remove a membrane pore. We here review what is known about the cellular and molecular mechanisms of membrane repair, with particular emphasis on the relevance of repair as it relates to disease pathologies. Collective evidence reveals membrane repair employs primitive yet robust molecular machinery, such as vesicle fusion and contractile rings, processes evolutionarily honed for simplicity and success. Yet to be fully understood is whether core membrane repair machinery exists in all cells, or whether evolutionary adaptation has resulted in multiple compensatory repair pathways that specialize in different tissues and cells within our body.
The cytoplasm is located inside of the cell between the nucleus and the cell membrane.
Some genetic mutations can be completely harmless, while others are life-altering. Mutations happen when DNA is copied incorrectly. This causes an irregularity in the DNA. Mutations are permanent changes to genetic material that can be passed on to offspring. These changes happen randomly and can occur in any type of gene. While some mutations are not harmful (hazel eyes, for example), many mutations have harmful effects on health.
