Answer:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.
Answer:
The most common elements, like carbon and nitrogen, are created in the cores of most stars, fused from lighter elements like hydrogen and helium. The heaviest elements, like iron, however, are only formed in the massive stars which end their lives in supernova explosions.
Explanation:
All the branches of science that deal with the scientific study of living organism are called life sciences. e.g; botany,zoology,anatomy,biochemistry,embryology etc..
That means <span>the fluid portion of the cytoplasm exclusive of organelles and membranes.</span>
English because of the laugueg
