"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.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.