No, the sickle-cell anemia allele won't be eliminated by natural selection.
Sickle-cell anemia trait is controlled by a single gene and the allele (S) for sickle-cell anemia is a harmful autosomal recessive. 
It is caused by a mutation in the normal allele (A) for hemoglobin (a protein on red blood cells).
Heterozygotes (AS) with the sickle-cell allele are resistant to malaria, a deadly tropical disease. It is common in many African populations.
In these areas, (S) carriers have been naturally selected, because their red blood cells, containing some abnormal hemoglobin, tend to be in sickle shape when they are infected by the malarial parasite.
Therefore, they are more likely to survive and reproduce. This keeps the S allele in the gene pool.
Learn more about Sickle-cell anemia on
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The lac repressor prevents the lac genes in the DNA of E. coli from being expressed most of the time. The answer to your question is A. I hope this is the answer that you are looking for and it comes to your help.
        
             
        
        
        
A fart ffffffffffffaaaaaaaaaaaaaarrrrrrrrrrrrtttttt
        
             
        
        
        
A because osmosis will act to balance the concentrations of water inside and outside the cell. As this happens, sugar outside the cell will dissolve into the water and be moved across the cell membrane with it into the cell. This continues until the concentrations are equal.
        
             
        
        
        
Answer:
The first three look like clear quartz then the last two might be obsidian 
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