Activity 43.1 how does the immune system keep the body free of pathogens

Explanation:

The immune system usually

respond to antigens, they tends to protects the body system from any possible harmful substances by recognizing the antigens then produce special form of protein which is reffered to as Antibodies.

The Antibodies is attached to an antigen and give room for the attraction of cells that will engulf the pathogens and then destroy the pathogen.They produce cells The immune system is made up of special cells such as phagocytes and lympocytes that directly attack the pathogen.

Antigens are substances which are usually proteins that lyes on the surface of cells, viruses, fungi, or bacteria. which induces an immune response in the body such as in the production of Antibodies .

The immune system recognizes and destroys substances that contain antigens.

of those who start drinking before they're 15 will develop alcohol dependence

i think the answer is

mass