| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.13 |
| Score | 0% | 63% |
Water freezing or boiling is an example of which of the following?
sublimation |
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phase transition |
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cooling |
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heating |
A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.
What prevents blood pumped out of the ventricles from flowing back into the heart?
capillaries |
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atria |
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platelets |
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valves |
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
Which of these is a type of Earth's crust?
terrestrial |
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metamorphic |
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sedimentary |
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oceanic |
The crust is the Earth's outermost layer and is divided into oceanic and continental types. Oceanic crust is 3 miles (5 km) to 6 miles (10 km) thick and is composed primarily of denser rock. Continental crust is 20 to 30 miles (30 to 50 km) thick and composed primarily of less dense rock. The crust makes up approximately one percent of the Earth's total volume.
Blood pressure is generally highest in which of the following?
arteries |
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capillaries |
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veins |
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heart |
Arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood.
Which of the following is true about species groups?
a population is made up of a group of communities |
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a biome is a made up of a group of biospheres |
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a community is made up of a group of populations |
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an ecosystem is a biological population |
A population is a group of organisms of the same species who live in the same area at the same time. A community is a group of populations living and interacting with each other in an area.