That is because all meridians start and end at the same point, unlike parallels that are parallel. Meridians all start at the north pole and go towards the south. Therefore, all of them meet at that point that is the north pole, so the distance between all of them is 0 miles.
Answer:
Such transport mechanism is called<u> Antiport.</u>
Explanation:
The production of hydrochloric acid (HCl) by the parietal cells requires the activity of the
enzyme, carbonic anhydrase.In the presence of carbonic anhydrase CO₂ and H₂O are converted to HCO⁻ and H⁻.
The newly generated proton (H+
)s transported into the lumen of the stomach via the e H
₊₋K
+ATPase (called the proton pump)Concurrently, HCO₃
⁻ exits from the basal surface (blood side) of the parietal cell via the HCO₃⁻
₋ Cl antiporter.
The chloride ionneeded to form HCl, enters the parietal cell from the blood via the HCO₃⁻₋Cl⁻ antiporter and exits at the luminal side by the Cl⁻ channel. Once within the lumen of the stomach, cl⁻ combines with H⁺to form HCl.
The luminal K⁺ that is needed to maintain the activity of the proton pump(H⁺₋K⁻ATPase)enters the parietal cells from the stomach lumen by the H⁺₋K⁺ + ATPase and is then recycled back into the lumen of the stomach by the K⁺ channel.
Genetic variation describes the genetic differences among individuals of the same species that are naturally occurring. <span>Each genotype within a population usually has different degrees of fitness to an environment. Mating between same species with favored genes guarantees survival of the population in their chosen environment. As the environment changes, the mating behavior between species may again change resulting to a different gene pool to guarantee survival. </span>
The answer is; B
Mutation is one source of variation (in addition to sex and gene flow). Mutations are rare and occur in a small proportion of individuals. However, due to the advantage that the genetic mutation confers to these individuals, their chances of passing the genes to the next generation is higher than that of the general population.
This way, the allelic frequencies of these advantageous mutated genes increase with each generation and eventually become the majority population over time.
