Answer:
(a) can be used to bend epithelial sheets into tubes.
Explanation:
The adherens junctions are cell-cell adhesions localized in places exposed to abrasion or mechanical stress, close to the apical membrane in epithelial cells is one of these locations. Some of their functions are the initiation and stabilization of cell-cell adhesion, <em>they join the actin cytoskeleton to the plasma membrane to form adhesive contacts between cells that contribute to the folding and bending of epithelial sheets,</em> therefore they can mediate adhesion and signaling.
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Answer:
Oldest fossils ever found show life on Earth began before 3.5 billion years ago.
Explanation:
I m pretty sure it’s the light x
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.
