<span>Factors that can increase mutation rates are high and low temperatures, food additives, and UV rays. All of these answers are correct. Mutation rates in genes vary depending on many environmental effects. UV rays, along with varying temperatures, can cause mutations during cell division due to the damage they impart on the cells that are dividing. Dangerous food additives are believed to cause mutations, as seen in animal studies (ie. aspartame causing cancer in rats).</span>
Covalent bonds are formed when two non metal atoms share an electron. The atoms either give up or gain an electron, due to the outer shell being unstable.
Answer:
In secondary succession, a previously occupied area is re-colonized following a disturbance that kills much or all of its community. A classic example of secondary succession occurs in oak and hickory forests cleared by wildfire. Wildfires will burn most vegetation and kill animals unable to flee the area.