As g ∝ 1/d² between two two components, further potential difference would result in lower gravitational pull. So the influence of gravitational pull among them also reduces as two things are isolated from the others.
The nerves in the integumentary system (skin) sense the irritation and send the signal to the brain. The brain then sends impulses through the nervous system to scratch the itch.
There are some examples where human hormone genes are excised and placed into bacterial DNA. An example of this is Human Growth Hormone, which is mass-produced for human use by bacteria.
