Answer:
igneous is by heat, sedimentary byayering and metaphoric by heat
Types of natural selection: Different types of natural selection can impact the distribution of phenotypes within a population.In (a) stabilizing selection, an average phenotype is favored.In (b) directional selection, a change in the environment shifts the spectrum of phenotypes observed.In (c) diversifyingselection.
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.
Biotic factors are anything in a ecosystem that is living, was living, or is going to live.
From this we can conclude that the biotic factors are remains of dead organisms and flora and fauna.
Temperature and minerals in the soil are abiotic, meaning they will never live.
