Answer:
Central nervous system:
Central nervous system consists of the brain and the spinal cord. Short nerve impulse are present in the central nervous system. The information are obtained from the sensory organs. The damage of nerve fibers are irreparable in the central nervous system.
Peripheral nervous system:
Peripheral nervous system consists of the motor neurons, sensory receptor and sensory neurons. Long nerve impulse are present in the peripheral nervous system. The information are pass out to the effector organs. The damage of nerve fibers are reparable in the peripheral nervous system.
Biotechnology can be used to transform bacteria so they are able to make human proteins, such as insulin. It can also be used to create transgenic crops, such as crops that yield more food or resist insect pests. (I copied this off the web so just paraphrase)
Convergent evolution would be the best way to explain why two species that look similar are not necessarily that closely related. In convergent evolution, distinct species develop similar anatomical characteristics after its divergence from one common ancestor that does not possess the initial characteristic.