<em>»Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body. At the same time, carbon dioxide that is dissolved in the blood comes out of the capillaries back into the air sacs, ready to be breathed out.</em>
<em>»Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body. At the same time, carbon dioxide that is dissolved in the blood comes out of the capillaries back into the air sacs, ready to be breathed out.</em>
<em>»Blood with fresh oxygen is carried from your lungs to the left side of your heart, which pumps blood around your body through the arteries.</em>
Animal pollinations give flowering plants reproductive advantages over gymnosperms. Take a bee for example. A bee may pollinate a flower, but the leftover pollen on the bee's body or wings can spread to other flowers.