T cell activation is initiated by an activated B cell.
The B cell presents antigens on its MHC receptors. The T cell recognizes the antigen bound to the MHC. There are other cosignals that fully activate the at cells but the antigen on the MHC receptor on the B cell is where it all starts.
D .............. im pretty sure its this one :)
the global sea level is rising and ocean temperatures are Increasing
Answer:
DNA is made of chains of four smaller molecules called "Nucleotides".
Explanation:
A molecule consisting of a nitrogen-containing base (adenine, guanine, thymine, or cytosine) in DNA is known as a nucleotides.
