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.
You would expect to find elastic fibers
The right answer for the question that is being asked and shown above is that: "TRUE." <span>An alluvial fan may form where a stream flows out of a narrow mountain valley, slows down, and deposits sediment. The statement is true as far as the alluvial fan is concerned.</span>
Chicken breast-protein
Banana-carbohydrate
(Sorry if I’m wrong about the banana, most of my sources said carbohydrates)
Answer: a compound known as calcium carbonate (CaCO3)
Explanation: Google the question itself