The mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid, making it an example of a missense mutation. Missense mutation is the mutation characterized with <span>changes in one base pair so that the whole amino acid is changed.</span>
Hurricanes are not an example of density dependent limiting factors!
The natural selection is the survival of the fittest, which means that o<span>nly the best adapted individuals survive and reproduce, contributing the most to the next generation</span>
According to natural selection, birds such as cardinals , eagles, and ducks have differently shaped feet due to <span>adaptation to different environments and feeding habits.
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Step 1. Simplify brackets

Step 2. Simplify
13
Done! :)
Your answer is A. 13 Hope this helps!