( ( Subscripted ( uppercase letters ) ) ( ( represent ( matrix blocks ) ) . ) )
(ROOT (S (NP (JJ Subscripted) (NN uppercase) (NNS letters)) (VP (VBP represent) (NP (NN matrix) (NNS blocks))) (. .)))
Subscripted uppercase letters represent matrix blocks.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (VP (VBD represented) (PP (IN by) (NP (DT a) (JJ single) (NN letter)))))) (, ,) (NP (JJ dominant) (NNS alleles)) (VP (VBP are) (VP (VBN represented) (PP (IN by) (NP (JJ uppercase) (NNS letters))))) (. .)))