| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.47 |
| Score | 0% | 69% |
Saturated fats can __________ LDL ("bad") cholesterol while unsaturated fats can __________ it.
raise, decrease |
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decrease, stabilize |
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decrease, raise |
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stabilize, raise |
Saturated fats can raise LDL ("bad") cholesterol while unsaturated fats can decrease it.
Velocity and displacement are fully described by both a magnitude and a direction. Velocity and displacement are which of the following?
combinational quantities |
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scalar quantities |
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composite quantities |
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vector quantities |
Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)
When light travels between two substances it bends. This is called:
convection |
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refraction |
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conduction |
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reflection |
Because different materials have different refractive indices, light changes speed when passing from one material to another. This causes the light to bend (refraction) at an angle that depends on the change in refractive index between the materials. The greater the difference, the higher the angle of refraction.
Which of the following is not a characteristic of the Sun?
formed 2.6 billion years ago |
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makes up over 99% of the mass of the solar system |
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is a yellow dwarf star |
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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.
Scavengers break down the dead bodies of plants and animals into which of the following?
simple nutrients |
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producers |
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carrion |
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complex carbohydrates |
Like decomposers, scavengers also break down the dead bodies of plants and animals into simple nutrients. The difference is that scavengers operate on much larger refuse and dead animals (carrion). Decomposers then consume the much smaller particles left over by the scavengers.