I think the answer is Specialized cells!
Water is a limited natural resource, vital for the expansion and development of, not only our specie, but each individual living organism in the planet. Hence, in a community proper water management is a must in order to make sure that water be maintained and cared for -used wisely. In one research, it is estimated that by 2025 more places will feel water scarcity than decades ago.
<span>D.Oxygen will diffuse from an area of higher concentration (outside the cell) to an area of lower concentration (inside the cell). This is because cells respire constantly, as this process uses up oxygen cells will contain less oxygen than its surroundings. Oxygen moves by the process of diffusion, in diffusion a molecule will always move from a higher concentration to a lower concentration.</span>
Answer:
Differential reproduction leads to a change in allele frequencies over time. This occurs because of natural selection favoring "successful" individuals that produce more viable offspring.
The sickle-cell allele is maintained in populations exposed to malaria through balancing selection, since heterozygous individuals have protection against the disease.