D:viruses are not killed by antibiotics.
The answer should be b: active transport
Natural selection<span> is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.</span>
The concave disc shape of red blood cells Maximizes the surface area of the cell , allowing for rapid movement of oxygen or carbon dioxide to and form the hemoglobin within the cell.
