| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.78 |
| Score | 0% | 76% |
This skeletal system is common in arthropods like insects, spiders, and crustaceans.
exoskeleton |
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bone |
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vertebrate |
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endoskeleton |
An exoskeleton (external skeleton) is common in arthropods like insects, spiders, and crustaceans.
Which of blood component fights infection?
red blood cells |
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plasma |
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white blood cells |
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platelets |
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.
A transition zone between two air masses is called:
fog |
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thunderstorm |
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front |
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boundary |
An air mass is a large body of air that has similar moisture (density) and temperature characteristics. A front is a transition zone between two air masses.
Arteries carry __________ blood at __________ pressure.
deoxygenated, low |
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oxygenated, high |
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oxygenated, low |
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deoxygenated, high |
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.
Which of the following is the narrowest classification of life?
species |
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genus |
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family |
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domain |
The narrowest classification of life, species, contains organisms that are so similar that they can only reproduce with others of the same species.