( ( ( Cold-blooded ( or ( ectothermic animals ) ) ) ( like ( ( reptiles or ) fish ) ) ) ( ( have ( ( body temperatures ) ( that ( change ( according ( to ( the ( surrounding temperature ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Cold-blooded) (CC or) (JJ ectothermic) (NNS animals)) (PP (IN like) (NP (NNS reptiles) (CC or) (NN fish)))) (VP (VBP have) (NP (NP (NN body) (NNS temperatures)) (SBAR (WHNP (WDT that)) (S (VP (VBP change) (PP (VBG according) (PP (TO to) (NP (DT the) (VBG surrounding) (NN temperature))))))))) (. .)))
Cold-blooded  or ectothermic animals like reptiles or fish have body temperatures that change according to the surrounding temperature.
(ROOT (S (NP (NNS Ectotherms)) (VP (VBP undergo) (S (NP (NP (DT a) (NN variety)) (PP (IN of) (NP (NP (NNS changes)) (PP (IN at) (NP (DT the) (JJ cellular) (NN level)))))) (VP (TO to) (VP (VB acclimatize) (PP (TO to) (NP (NP (NNS shifts)) (PP (IN in) (NP (NN temperature))))))))) (. .)))