The circulatory aids with the immune system because they provide white-blood cells to help fight with the diseases or sicknesses.
A little bit less than a purposely discovery. A discovery that you've been looking for for a while would be like 75% of discovering but accidentally would be 35% of actually discovering something accidentally.
Answer: from the pulmonary veins into the left atrium.
Explanation:
After oxygenation of blood in the lungs, the right and left pulmonary veins carry oxygenated blood and empties it into the left atrium. The left atrium then empties the blood into the left ventricle through the left atrioventricular valve.
With contraction, the ventricle pumps the blood to the systemic circulation through the aorta. The blood flow into the aorta is guarded by the aortic valve.
Answer:
A phospholipid is consists of a glycerol backbone with a 2 fatty acids (either saturated or unsaturated) attached to it and a phosphate group, hence forming the head of the phospholipid molecule. I have attached a photo below for your reference.