( ( A ( eukaryotic ribosome ) ) ( ( is ( composed ( ( ( of ( ( five kinds ) ( of rRNA ) ) ) and ) ( about ( ( eighty kinds ) ( of proteins ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (JJ eukaryotic) (NN ribosome)) (VP (VBZ is) (VP (VBN composed) (PP (PP (IN of) (NP (NP (CD five) (NNS kinds)) (PP (IN of) (NP (NN rRNA))))) (CC and) (PP (IN about) (NP (NP (JJ eighty) (NNS kinds)) (PP (IN of) (NP (NNS proteins)))))))) (. .)))
A eukaryotic ribosome is composed of five kinds of rRNA and about eighty kinds of proteins.
(ROOT (S (NP (DT A) (NN ribosome)) (VP (VBZ consists) (PP (IN of) (NP (NP (CD two) (NNS elements)) (, ,) (NP (NN rrna)) (CC and) (NP (NNS proteins))))) (. .)))
A ribosome consists of two elements, rrna and proteins.