| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.95 |
| Score | 0% | 59% |
Blood is created in:
the liver |
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the heart |
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red blood cells |
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bone marrow |
Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.
In the heart, blood flows from the right __________ to the lungs then back to the heart via the left __________.
ventricle, ventricle |
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atrium, atrium |
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ventricle, atrium |
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atrium, ventricle |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.
A major difference between sound waves and light waves is which of the following?
a sound wave is mechanical while a light wave is electromagnetic |
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all of these are correct |
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a sound wave cannot travel through a vacuum |
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a sound wave is much slower than a light wave |
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.
Which of the following is not a characteristic of the Sun?
formed 2.6 billion years ago |
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is a yellow dwarf star |
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makes up over 99% of the mass of the solar system |
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is composed of hydrogen and helium |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.
During continental drift, the drifting plates move across which of the following?
water |
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liquid mantle |
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sediment |
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fault lines |
The crust and the rigid lithosphere (upper mantle) is made up of approximately thirty separate plates. These plates more very slowly on the slightly more liquid mantle (asthenosphere) beneath them. This movement has resulted in continental drift which is the gradual movement of land masses across Earth's surface. Continental drift is a very slow process, occurring over hundreds of millions of years.