Answer:
Each villus, in turn, has thousands of even smaller projections called microvilli (singular: microvillus).
Explanation:
The villi contain capillaries, which are tiny blood vessels. Nutrients are absorbed into these capillaries across the surfaces of the villi and microvilli. Because there are millions of these tiny projections, they greatly increase the surface area for absorption.
Answer:
E. Population - community - ecosystem - biosphere
Explanation:
Population is the set of organisms of the same species
Community is where organisms of different species live and communicate together
ecosystem is a biological system where ocommunities and environment are present.
Biosphere is where all ecosystem are present. (let´s say, the earth)
Natural selection is the process by which individuals who are best suited to the environment tend to leave (on average) more offspring than others.
Evolutionary changes take place over many generations and through millions of years of natural selection. For the genes to survive, they must be among the strongest.
I would say oxygen because respiration is breathing mechanically.
