3
Ordering
4 points
Number the following events of V(D)J recombination in the correct order in which they occur.
The Rag1/Rag2 cuts the DNA, forming a hairpin.
Rag1 and Rag2 bind to the recombination signal sequences found in genes the T cell receptor.
The V, D, or J segments are joined and ligated together.
Opening of the DNA hairpin.
Random addition or subtraction of DNA bases at the coding ends between V, D, or J segments.