( ( ( ( These ( have ( cellulosic plates ) ) ) and ) ( ( their alveolus ) ( is ( ( a ( deep groove ) ) ( between ( the plates ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT These)) (VP (VBP have) (NP (JJ cellulosic) (NNS plates)))) (CC and) (S (NP (PRP$ their) (NNS alveolus)) (VP (VBZ is) (NP (NP (DT a) (JJ deep) (NN groove)) (PP (IN between) (NP (DT the) (NNS plates)))))) (. .)))
These have cellulosic plates and their alveolus is a deep groove between the plates.
(ROOT (S (NP (NP (DT The) (NNS lungs)) (PP (IN of) (NP (NNS mammals)))) (VP (VBP are) (ADJP (JJ unique) (PP (IN in) (S (VP (VBG having) (NP (NNS alveoli))))))) (. .)))