( ( ( ( ( Cells ( vary ( in ( ( size ( as ( well as ) ) ) shape ) ) ) ) , ) but ) ( ( all cells ) ( are ( very small ) ) ) ) . )
(ROOT (S (S (NP (NNS Cells)) (VP (VBP vary) (PP (IN in) (NP (NP (NN size)) (CONJP (RB as) (RB well) (IN as)) (NP (NN shape)))))) (, ,) (CC but) (S (NP (DT all) (NNS cells)) (VP (VBP are) (ADJP (RB very) (JJ small)))) (. .)))
Cells  vary in size as well as shape, but all cells are very small.
(ROOT (S (NP (DT All) (NNS cells)) (VP (VBP have) (NP (NP (DT the) (JJ small) (NN size)) (PP (IN in) (NP (JJ common))))) (. .)))