Motor neurons carry impulses to the effectors in the body, which are the muscles or glands that produce a change based on a stimulus sensed by the receptors. The motor neurons "innervate" muscle fibers, which essentially means that they cause them to move. The fewer the muscle fibers associated with a motor neuron, the more precise are the movements of those fibers. Having to control a small number of fibers, the neuron is able to coordinate more dexterous motions. An example of a region where there are not a lot of muscle fibers related to each neuron is in your fingers.
I think this is an theory changing because a new scientific method was developed. They used what Mendel had learned to test the hypothesis themselves and discovered that he was right.
Both the pelvis and femur of a whale are called vestigial structures! Another example of this is a human’s tail bone. Hope this helped!
The best and most correct answer among the choices provided by your question is the fourth choice or letter D. Reptiles are the most critically endangered animal group. Their population is threatened due to illegal activities done by man like poaching.
I hope my answer has come to your help. Thank you for posting your question here in Brainly.