Destruction of myelin will affect the nerve and there will be the less conduction of electrical impulses from the brain to other parts of the body and the nerve signal sent to the brain are delayed. These damaged nerve areas form sclerosis which disrupts the signalling capacity of the nerve. This may occur due to genetic defects, infectious agents, auto immune reactions and trauma.
D. 99% of all living things that have ever existed are now extinct
This phenomenon can be explained by Allen's rule. It says that the body proportions and shape may vary in different climates. The temperature decreases as the latitude increases, so in the northern region is much colder. Animals must preserve heat in such conditions. So, exposed surface areas of the body, such as the ears, feet, and tail, are usually minimized to minimize heat loss in the cold climate. <span>Therefore, northern species often have smaller ears, feet, and tail than the southern species. </span>
That property is called h<span>ydrogen bonding. </span>