| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.99 |
| Score | 0% | 60% |
Which of the following is not a characteristic of the Sun?
makes up over 99% of the mass of the solar system |
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is a yellow dwarf star |
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formed 2.6 billion years ago |
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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.
As part of digestion, the liver produces bile which breaks down:
fat |
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protein |
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starches |
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sugars |
The liver produces bile which emulsifies (separates) fat.
Arteries carry __________ blood at __________ pressure.
oxygenated, high |
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deoxygenated, low |
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deoxygenated, high |
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oxygenated, low |
Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.
Secondary consumers that also eat producers are known as:
carnivores |
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herbivores |
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omnivores |
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scavengers |
Secondary consumers (carnivores) subsist mainly on primary consumers. Omnivores are secondary consumers that also eat producers. Examples are rats, fish, and chickens.
In the heart, blood flows from the right __________ to the lungs then back to the heart via the left __________.
atrium, atrium |
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ventricle, atrium |
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atrium, ventricle |
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ventricle, 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.