carbon dating shows how old a bone is by measuring the amount of carbon 12, and carbon 14 that the bone contains. and because carbon 14 is not replaced by exchange with the atmosphere the ratio of c12:c14 (the ratio of carbon 12 to carbon 14) tells how old the bone is by comparing the amount of carbon 14 to the amount of carbon 12. carbon 14 has a half life of 5,700 years, while carbon 12 is stable and does not radioactively decay at all.
Answer: <em>The Bottleneck Effect</em>
Explanation:
A Bottleneck effect is the sharp reduction of numbers of a population through environmental effects or human activity. It causes a loss of the genetic pool and its variety; genetic variation lowers and increases with time as random mutations occur.
Answer:
Sympathetic Nervous System.
Explanation:
Sympathetic nervous system is one of the parts of Autonomic nervous system and the other part is Parasympathetic nervous system.
As a whole the autonomic nervous system controls the unconscious responses of our body.
The main function of the Sympathetic nervous system is to stimulate the 3F response of the body. Here 3F refers to Fight, Flight and Freeze. Adrenal gland is stimulated by this system which secretes adrenaline. Due to the effect of adrenaline heart neat increases, blood pressure increases, pupils dilate, sweat glands are activated, peristalsis in the gut is inhibited, and kidney secretion increases.
