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.
Answer:
6
Explanation:
Cause after 6 the graphed line stays the same, which means it stopped growing.
It occurs in the first phase known as the Prophase. During this the chromosomes inside the cell’s nucleus condense to form tight structures.
