How does the immune system recognize diverse possible antigens? •how do antibodies simultaneously recognize a huge variety of antigens and carry out a limited number of effector functions? •what is v(d)j recombination? what do the letters (and parentheses) signify? •what is the 12/23 rule? •what are rag-1/2 and tdt? what do they recognize? what do they do? •what changes at the ig loci are required to switch from membrane-bound to secreted ig?

check the explanations

Explanation:

1.- The immune system recognize antigens because both are complementary proteins, they match like in a puzzle, just to the exact shape and not to another that is similar.

2.- Since each antibody has a different shape, that is unique, so it will recognize just one kind of protein.

3.- Variable (diversity) joining, is a genetic recombination that occurs in the lymphocytes to produce antibodies.

4.- The rule 12/23 is apply when a protein is in the process of recombination of the DNA, if the recombination occurs in just one chain so just 12 basepairs are working, but if there are 2 strains, then 23 basepairs are included.

5.- The recombination activation gene (RAG)  codify enzymes for the reorder and recombination of the inmunoglobine and the linphocytes T.

6.- Is a Loci in the genetic code for a cancer gene, could be turn "off" and when is in contact with some factors could be "on" and produce cancer.

oxygen +1 most likely