<span> a characteristic of acids is that they react with metals to release hydrogen gas.</span>
B:2 it is measured by the crest of the wave or as I say the top of the wave
Answer:
many
pollution by dumping chemical that are harmful to the animals
littering by plastic
accidentally introducing invasive species
over fishing
it lowers the biodiversity of the aquatic ecosystems living there
Explanation:
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.