Answer: c. Some health risks are increased by heredity, which manifest under certain environmental conditions.
Explanation:
Many abiotic factors (non-living factors) such as radiations, hazardous substances present in the environment such as air, water and soil may originate from the industries, mining practices, fossil fuels and landfills. Some of the substances are carcinogenic and mutagenic in nature. These are capable of affecting the genetic make up of the organism. The genetic variations or mutations occurs may transmit from the parent to the offsprings.
Therefore, on the basis of the above information, c. Some health risks are increased by heredity, which manifest under certain environmental conditions. is the correct option.
Saturated hydrocarbons consists of C-C single bond whereas Unsaturated hydrocarbons consists C-C double/triple bond.
solution:
You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. 
Within the visible range of light, red<span> light waves are scattered the least by atmospheric gas molecules. So at sunrise and </span>sunset, when the sunlight travels a long path through the atmosphere to reach our eyes, the blue light has been mostly removed, leaving mostly red<span> and yellow light remaining.</span>
1 gallon of antifreeze = 60% of mixture. Total mixture:
Vm = 1/0.6
= 1.67 gallons
Volume of water = total vol - antifreeze vol
= 1.67 - 1
= 0.67 gallon of water
