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.
 
        
             
        
        
        
As elevation increases, air density decreases resulting in a decreased ability to hold heat.
<h3>Effect of elevation on climate</h3>
As you increase in elevation, there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further and the temperature decreases.
P = ρgh
where;
- P is the air pressure
- ρ is air density
- h is elevation
- g is acceleration due to gravity
As the pressure decreases, air molecules spread out further and the temperature decreases. The decrease in temperature affects the amount of heat that air can hold.
Thus, as elevation increases, air density decreases resulting in a decreased ability to hold heat.
Learn more about effect of elevation on climate here: brainly.com/question/463893
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C. Matter is anything that is made of atoms and has mass.
        
                    
             
        
        
        
Many physical disorders that occur in humans are attributed to the styles of living and general eating habits. Conditions such as diabetes, depression, dymentia and even some cancers are led by bad eating habits. A friend once asked me: Now that I do not want to become obesse but want to be muscular, what will I do since I have to gain mass but I don't want to overfeed? My answer was so simple. EXERCISE
Exercise can be in many forms. The most common modes of exercise are gym and athletics. If you don't do regular exercise, your body does not find a chance to get rid of the many wastes produced by different metabolic processes. Some of these products are toxic and they lead to bad effects in the body. The effect is getting lifestyle diseases.
Exercise plays a key role in boosting your memory. During and after exercise, blood becomes more oxygenated and the supply of oxygenated blood to the brain is increased. This ensures there is renewed strength in the brain parts e.g. hypothalamous and hence boosting thinking ability.
We can not overlook the fact that exercise is fun. When exercising, you are happy and happiness makes you stay healthy.
        
             
        
        
        
Answer:
Explanation:
A population distribution shows _______.
a. the distribution of age groups within a population
b. the amount of organisms in a unit area
c. the total number of organisms in a population
d. where and in what arrangement organisms are located Please select the best answer from the choices provided