In the immune response, the phase in which killer t cells strike at foreign cells and at cells of the body that have been invaded and infected is called

Cell mediated immune response

Explanation: The immune response could be either humoral or cell mediated. Humoral is use of antibodies to kill the pathogens and infection. In cell mediated immune response, immune cells like T cells, phagocytes, etc are used to kill the pathogens or infected cells. Killer T cells get activated when they get signal from other proteins of the immune system.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.