( ( ( ( Bacteria , ) ( for example ) ) , ) ( ( may ( divide ( ( several times ) ( per hour ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Bacteria)) (, ,) (PP (IN for) (NP (NN example))) (, ,)) (VP (MD may) (VP (VB divide) (NP (NP (QP (JJ several) (NNS times))) (PP (IN per) (NP (NN hour)))))) (. .)))
Bacteria, for example, may divide several times  per hour.
(ROOT (S (NP (NNS Bacteria)) (VP (MD may) (VP (VB divide) (NP (NP (QP (JJ several) (NNS times))) (NP (DT an) (NN hour))))) (. .)))