SI Units A young oak tree has 5268 leaves. The average surface area is 42 cm2 per leaf. Which of these best represents the total surface area of the leaves on this tree? 220 cm2 220000 cm2 220 m2 220000 m2   The average adult has a system of blood vessels about 80,000 meters long. That is equal to 80 kilometers 800 kilometers 8000 kilometers 8 kilometers   Your body contains about 5000 milliliters of blood. That is equal to 5000 centimeters 500 liters 50 cm3 5 liters   Your body contains about 5 million red blood cells. These cells have a short lifespan and every 100 days all the red blood cells in your body have been replaced. Which of these best represents the rate at which red blood cells are produced in the body? 5000 cells/day 50000 cells/day 5000000 cells/day 3000 cells/hour   Your two lungs have a total mass of 1.2 kilograms. The mass of one of your lungs is 0.6 grams 600 milligrams 600 grams 600 micrograms   At rest, your heart pumps about 5 liters of blood a minute. Which of these represents the amount of blood pumped by the heart in one day? 300 liters 18000 milliliters 7200 liters 500 liters   The total length of the digestive system in an average adult is 81/2 meters. That is equal to 8500 centimeters 8500 millimeters 8500 micrometers 8500 decimeters   The DNA in a human cell measures a total length of 1800 millimeters. That is equal to 1.8 meters 1.8 centimeters 1.8 decimeters 1.8 dekameters   The refractory period, the time between signals in which a neuron cannot be stimulated, is 0.0004 second. That is equal to 1/10,000   of a second 4/10,000   of a second 1/1000   of a second 4/1000   of a second   The human kidney filters about 180000 milliliters of fluid from the blood every day. That is equal to 0.18 liters 1.8 liters 18 liters 180 liters   According to this graph of hourly measurements, the optimum temperature for photosynthesis is 18 oC 22 oC 23 oC 25 oC   According to the graph, what total volume of water was produced at a temperature of 25 oC? 1 cm3 7 cm3 14 cm3 21 cm3