<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>
The answer for Part A is: In an action-reaction pair the forces work on different objects.
<span>Your answer is Precambrian.</span>
As the left ventricle contracts, oxygenated blood leaves the heart through the aortic valve, into the aorta. The blood to lower limb flows through descending aorta, which continues down to Left Common Femoral Artery, which continues down to Left Superficial Femoral Artery, which continues down to Left Popliteal Artery. The Left Popliteal Artery gives 2 divisions.
1. Left Tibioperoneal Artery (which continues down to the Left Posterior Tibial Artery which supplies back of the foot.)
2. Left Anterior Tibial Artery (which continues down to Left Dorsalis Pedis Artery which continues down to <em>Left First Dorsal Metatarsal Artery</em> which supplies the big toe/first digit of foot.)