Answer:
Option "C" Oxygen is the correct answer to the following question:
Explanation:
We know that, Just as a human absorbs oxygen into the body through inhalation, the oxygen enters into the whole body also in the blood and is used in the body by cells, so we can say that the human body needs a constant supply of oxygen. therefore, the appropriate option is true
 
        
             
        
        
        
Closely related but different, distantly related but similar
        
             
        
        
        
Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
 
        
             
        
        
        
I do not think the industrial and agricultural revolutions could have occurred without the environmental costs. The industrial revolution in the 18th century occurred at a time in history when people where not aware of the consequences of their actions or the consequences of the widespread use of fossil fuels. Even if they were aware the technology would not have been present to harness power from natural renewable sources of energy. 
        
             
        
        
        
This is the case since earthquakes form directly from tectonic plates. It happens when 2 tectonic plates pass by each other and causes fiction from the bumby sides of the plates