( ( As ( it rises ) ) ( it ( ( undergoes ( adiabatic ( temperature changes ) ) ) . ) ) )
(ROOT (S (SBAR (IN As) (S (NP (PRP it)) (VP (VBZ rises)))) (NP (PRP it)) (VP (VBZ undergoes) (NP (JJ adiabatic) (NN temperature) (NNS changes))) (. .)))
As it rises it undergoes adiabatic temperature changes.
(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))))))))) (. .)))