( ( ( Protons and ) neutrons ) ( ( are ( made ( from ( ( smaller particles ) ( called quarks ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN from) (NP (NP (JJR smaller) (NNS particles)) (VP (VBN called) (NP (NNS quarks))))))) (. .)))
Protons and neutrons are made from smaller particles called quarks .
(ROOT (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (NNS quarks)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (NP (NP (JJ fundamental) (NNS particles)) (PP (IN of) (NP (NN matter))))))))))) (. .)))