| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
Which of the following is true about species groups?
a community is made up of a group of populations |
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a biome is a made up of a group of biospheres |
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a population is made up of a group of communities |
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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.
Momentum is a measure of how difficult it is for a moving object to stop. Which of the following is the formula for momentum?
none of these |
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\(\vec{p} = {m \over \vec{v}}\) |
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\(\vec{p} = m\vec{v}\) |
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\(\vec{p} = { \vec{v} \over m}\) |
Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's mass by its velocity: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.
Regulation of heart rhythm occurs in:
nerves |
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cerebrum |
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medulla |
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cerebellum |
Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.
The coldest point in the Earth's atmosphere is reached in which atmospheric layer?
stratosphere |
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troposphere |
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mesosphere |
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thermosphere |
In the mesosphere, temperature again drops as altitude increases until the coldest point in the Earth's atmosphere, the mesopause, is reached where temperatures fall to −225 °F (−143 °C).
The gravitational interaction of Earth and the Moon is responsible for which of these?
day and night cycle |
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tides |
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seasons |
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the northern lights |
Tides are caused by the gravitational interaction of Earth and the Moon.