When the activities of a cell, tissue, organ, or system change automatically due to environmental variation, the homeostatic mechanism that operates is called

Autoregulation

Explanation:

When the activities of a cell, tissue, organ, or system change automatically due to environmental variation, the homeostatic mechanism that operates is called autoregulation.

Autoregulation is a method of controlling the local blood circulation. It is characterized as an organ's inherent capacity to sustain a standard blood flow, given changes in the pressure of the perfusion.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called