Answer:
To achieve precipitation of the DNA.
Explanation:
Isopropyl alcohol makes the DNA sediment. The DNA, once out of the solution, becomes visible, as it clumps.
The result of adding isopropyl alcohol is the precipitation or sedimentation of DNA when DNA becomes like a visible thread with the help of alcohol and salt. The precipitation of DNA is important because it removes the dirt from DNA.
“It is a type of homogeneous mixture.” is false.
Start with two facts about water. 1) Water has a high specific heat capacity and 2) water has a high heat of vaporization. So you can discard the other two answers.
The specific heat capacity is the amount of heat that a substance need to increase its temperature 1 °C. The bigger the specific heat capacity the more heat is needed to increase the temperature of the substance. Then it is the high specific heat capacity of water what prevents that its temperature increase very rapidly when the sun heats it, which in turn avoids that the water evaporates too fast.
Then, the answer is the high specific heat capacity.
