<prompt> T - cells mature in?Bone marrowLiverThymusLymph nodes  <response>: Ans is c i.e., Thymus o T cell precursors arise in bone marrow also in yolk sac liver before birth and migrate to the thymus. Maturity of T-cells takes place in the thymus So, T cells arise in bone marrow and mature in thymus.o B cells originate as well as mature in bone marrow. 