effector t cells that directly kills foreign cells, cancer cells, or virus-infected body cells by inducing apoptosis(cell suicide) ??? ??? ??? spleen contains white pulp( immune functions) and red pulp (disposing of worn-out red blood cells) ??? ??? ??? thymus function site of maturation of t lymphocytes ??? ??? ??? tonsils are the simplest lymphoid organs. ??? ??? ??? palatine tonsils largest of