| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.58 |
| Score | 0% | 72% |
Water has a refractive index of 1.33. Which of the following is true?
light is 1.33 times brighter in a vacuum than it is in water |
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light is 1.33 times dimmer in a vacuum than it is in water |
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light travels 1.33 times faster in a vacuum than it does in water |
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light travels 1.33 times slower in a vacuum than it does in water |
The speed of light varies based on the material that the waves are passing through. The refractive index of a material indicates how easily light travels through it compared to how easily light travels through a vacuum. For example, the refractive index of water is 1.33, meaning that light travels 1.33 times faster in a vacuum than it does in water.
Saturated fats can __________ LDL ("bad") cholesterol while unsaturated fats can __________ it.
decrease, stabilize |
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decrease, raise |
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raise, decrease |
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stabilize, raise |
Saturated fats can raise LDL ("bad") cholesterol while unsaturated fats can decrease it.
In the food chain, bacteria and fungi convert the organic matter in the dead bodies of plants and animals into simple nutrients. Bacteria and fungi are:
scavengers |
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primary consumers |
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decomposers |
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producers |
Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.
What prevents blood pumped out of the ventricles from flowing back into the heart?
capillaries |
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valves |
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atria |
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platelets |
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 foods should a person with high cholesterol avoid?
vegetable oils |
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eggs |
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avocados |
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olive oil |
Fats come in three types, saturated (meats, shellfish, eggs, milk), monounsaturated (olives, almonds, avocados), and polyunsaturated (vegetable oils). Saturated fats can raise LDL ("bad") cholesterol while unsaturated fats can decrease it.