Through the process of transformation. Hope this helps.
An antigen is recognized by lymphocytes to be foreign and causes an immune response. It is important to know about the immune system of the body as well. The immune system is the system that recognizes and defends itself against any viruses, bacteria or any other harmful foreign bodies.
Mor i think but i could be wrong i suggest looking for more answer before you use mine.
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i BELEIVE THE ANSWER TO BE :C:
False, other way around. when oxygen is not present.