| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.13 |
| Score | 0% | 63% |
The rate of vibration of sound is called:
frequency |
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period |
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volume |
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amplitude |
The rate of vibration of sound is called frequency and is measured in hertz (Hz). One hertz is one repetition per second and sounds with high frequency have a higher pitch than sounds with lower frequency. Humans can hear sounds in the range of 20 Hz to 20 kHz.
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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an ecosystem is a biological population |
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a community is made up of a group of populations |
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.
Convert 0C° to F°.
32 |
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-32 |
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16 |
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0 |
To convert from C° to F° use:
\(F° = {9 \over 5}C° + 32\)
\(F° = {9 \over 5}(0) + 32\)
\(F° = 0 + 32 = 32\)
Neurons are part of the __________ nervous system.
somatic |
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peripheral |
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autonomic |
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central |
The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.
What prevents blood pumped out of the ventricles from flowing back into the heart?
platelets |
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valves |
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atria |
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capillaries |
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.