American Sign Language (ASL) is a natural language that serves as the predominant sign language of Deaf communities in the United States and most of anglophone Canada.
Adaptive immunity refers to antigen-specific immune response. The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen.
In biology, an adaptation, also called an adaptive trait, is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection.