Ancient organism remains, fossil layers, similarities among organisms alive today, similarities in DNA and similarities of embryos.
Answer: what the girl said above what right
I think it's true hope I helped:)
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.
Any occurence of extra chromosones is due to genetic mutation/disorders.
