( It ( ( ( ( is ( needed ( by ( ( every cell ) ( in ( the body ) ) ) ) ) ) and ) ( is ( ( a ( key ( building block ) ) ) ( of ( cell membranes ) ) ) ) ) ; ) )
(ROOT (S (NP (PRP It)) (VP (VP (VBZ is) (VP (VBN needed) (PP (IN by) (NP (NP (DT every) (NN cell)) (PP (IN in) (NP (DT the) (NN body))))))) (CC and) (VP (VBZ is) (NP (NP (DT a) (JJ key) (NN building) (NN block)) (PP (IN of) (NP (NN cell) (NNS membranes)))))) (: ;)))
It is needed by every cell in the body and is a key building block of cell membranes;
(ROOT (S (NP (NNS Cells)) (VP (VBP are) (NP (NP (DT the) (VBN specialized) (NN building) (NNS blocks)) (PP (IN of) (NP (PRP$ your) (NN body))))) (. .)))