"helmholtz’s study of nerves in the frog showed that a. there was specificity in sensory nerves b. there was specificity in motor nerves c. nerves conducted on an all or none basis d. the speed of neural transmission was measureable"

The answer is D; The speed of neural transmission is measurable

Explanation:

Helmholtz constructed an apparatus specially to measure short time intervals of the order of ten-thousandths of a second, Helmholtz was able, in an elegant experiment published in 1850, to measure precisely the speed of conduction of the nerve signals in the motor nerve of the frog's leg.

human-caused climate hope this

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".