The correct answer is that "the T cell enters a state of anergy".
The activation of T cells requires two signals: (1) antigen specific signal presented by an antigen presenting cell (either a macrophage or a dendritic cell) that activates t cell receptors and (2) co-stimulatory signals that is not antigen specific but rather found in the plasma membrane of the antigen presenting cell (i.e. CD28). In the absence of a co-stimulatory signal, the t cell will enter a state of anergy or the inability to produce an immune response toward an offending antigen.
Answer:
In primary succession, newly exposed or newly formed rock is colonized by living things for the first time. In secondary succession, an area that was previously occupied by living things is disturbed, then re-colonized following the disturbance.
Probably water. Abiotic means not living, such as sunlight or water.
The answer to this question is lactic acid. The reason why sports psychologists would need to look for a buildup of this chemical is because it is the chemical that produces pain or "feeling the burn" in an exercise when someone pushes their limit. Also, after so long, a person with a lactic acid buildup needs to take a break because high levels of lactic acid is dangerous for the bloodstream.
When working out, it's important to not only craft and individualized workout that works best for your body, but to make each workout focus on a specific area of the body, so that each area gets a particular amount of focus.