( ( Organisms ( which ( are ( able ( to ( ( use ( metabolic heat ) ) ( to ( maintain ( ( a ( constant ( body temperature ) ) ) ( that ( is ( higher ( than ( ( the temperature ) ( of ( the ( surrounding environment ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ( ( are ( called endotherms ) ) . ) )
(ROOT (S (NP (NP (NNS Organisms)) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (ADJP (JJ able) (S (VP (TO to) (VP (VB use) (NP (JJ metabolic) (NN heat)) (S (VP (TO to) (VP (VB maintain) (NP (NP (DT a) (JJ constant) (NN body) (NN temperature)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (ADJP (ADJP (JJR higher)) (PP (IN than) (NP (NP (DT the) (NN temperature)) (PP (IN of) (NP (DT the) (VBG surrounding) (NN environment))))))))))))))))))))) (VP (VBP are) (VP (VBN called) (NP (NNS endotherms)))) (. .)))
Organisms which are able to use metabolic heat to maintain a constant body temperature that is higher than the temperature of the surrounding environment are called endotherms.
(ROOT (S (NP (NNS Endotherms)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (NNS organisms)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (VP (VB maintain) (NP (DT a) (JJ stable) (NN body) (NN temperature)) (ADVP (RB even)) (PP (IN in) (NP (NP (DT the) (NN face)) (PP (IN of) (NP (NP (JJ large) (NNS fluctuations)) (PP (IN in) (NP (DT the) (JJ environmental) (NN temperature))))))))))))))) (. .)))