<span>The sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. The parasympatheticnervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.</span>
The answer is b. is under purifying selection
because water is continuously cycled from land to the atmosphere and back
Explanation:
With careful management and responsible usage, water is a renewable resource.
Using the concept that :
<span>The skin cell has twice the number of chromosomes as the sperm cell has.
</span>Hence,
<span>The sperm cell has 39 chromosomes.
The skin Cell will have = 39 x 2
= 78 </span><span>chromosomes.</span>