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The antigen-antibody immunological reaction is used to be regarded as typical of immunological responses. Antibodies are proteins synthesized by specialized cells called plasma cells, which are formed by lymphocytes (cells from the lymph system) when an antigen, a substance foreign to an organism's body, comes in contact with lymphocytes. Two important manifestations of antigen-antibody immunity are lysis, the rapid physical rupture of antigenic cells and the liberation of their contents into the surrounding medium, and phagocytosis, a process in which antigenic particles are engulfed by and very often digested by macrophages and polymorphs. The process of lysis is executed by a complex and unstable blood constituent known as complement, which will not work unless it is activated by a specific antibody; the process of phagocytosis is greatly facilitated when the particles to be engulfed are coated by a specific antibody directed against them.

What are antibodies?

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Though he worked hard, but he failed.

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unable to be destroyed or removed.

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To bite off more than one can chew

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“Do you really come from Spain?” said the Queen.

Fitness can be achieved only through

Which of the following is a risk factor for osteoporosis?

Homeostasis is the condition in which the body maintains