Question

which of the following is an odd one w.r.t types of lymphoid organs? a] bone marrow b] thymus c]bursa of fabricius d] lymph nodes

Answer 1

Ans d. Lymph nodes are secondary lymphoid organs. Thymus and bone marrow are primary lymphoid organs in us. As birds have hollow bones and bone marrow is absent in them, bursa of fabricius is the primary lymphoid organ in birds.