( ( In humans ) ( , ( ( light intensity ) ( ( is ( measured ( by ( ( the ( ( rods and ) cones ) ) ( of ( the retina ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NNS humans))) (, ,) (NP (JJ light) (NN intensity)) (VP (VBZ is) (VP (VBN measured) (PP (IN by) (NP (NP (DT the) (NNS rods) (CC and) (NNS cones)) (PP (IN of) (NP (DT the) (NN retina))))))) (. .)))
In humans, light intensity is measured by the rods and cones of the retina.
(ROOT (S (NP (NP (DT The) (JJ light-sensing) (NNS cells)) (PP (IN in) (NP (DT the) (NN retina)))) (VP (VBP are) (VP (VBN called) (NP (NNS rods) (CC and) (NNS cones)))) (. .)))