( ( ( ( a ( swarmer cell ) ) ( which ( posesses ( ( ( a ( single ( polar flagellum ) ) ) and ) ( a non-motile ) ) ) ) ) ( stalked cell ) ) . )
(ROOT (NP (NP (NP (DT a) (NN swarmer) (NN cell)) (SBAR (WHNP (WDT which)) (S (VP (VBZ posesses) (NP (NP (DT a) (JJ single) (JJ polar) (NN flagellum)) (CC and) (NP (DT a) (NN non-motile))))))) (VP (VBN stalked) (NP (NN cell))) (. .)))
a swarmer cell which posesses a single polar flagellum and a non-motile stalked cell.
(ROOT (S (PP (IN In) (NP (NNS humans))) (, ,) (NP (DT the) (NN sperm) (NN cell)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN cell)) (PP (IN with) (NP (DT the) (NN flagella) (NN structure))) (SBAR (WHNP (WDT that)) (S (VP (VBZ enables) (ADVP (RB motility))))))) (. .)))