( ( ( Flagella and ) cilia ) ( ( are ( extensions ( of ( ( the ( plasma membrane ) ) ( of ( many cells ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Flagella) (CC and) (NNP cilia)) (VP (VBP are) (NP (NP (NNS extensions)) (PP (IN of) (NP (NP (DT the) (NN plasma) (NN membrane)) (PP (IN of) (NP (JJ many) (NNS cells))))))) (. .)))
Flagella and cilia are extensions of the plasma membrane of  many cells.
(ROOT (S (NP (DT The) (NN plasma) (NN membrane)) (VP (VBZ controls) (SBAR (WHNP (WP what)) (S (VP (VBZ goes) (PRT (RP in) (CC and) (RP out)) (PP (IN of) (NP (DT a) (NN cell))))))) (. .)))
The plasma membrane controls what goes in and out of a cell.