Dysmetria is seen in lesions of
Basal ganglia
Cerebellum
Pons
Cerebral coex
Dysmetria is manifested by past pointing in the cerebellum. The cerebellum controls all aspects of movements like rate, range, direction & force of movement, hence ataxia is a prominent feature of the cerebellar disease Ref : Ganong 25th ed/page 248
Nervous system