| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
__________ and __________ pair to strengthen bones.
vitamin D, calcium |
|
vitamin D, magnesium |
|
iron, calcium |
|
calcium, vitamin A |
Vitamin D helps calcium strengthen bones while also aiding muscle, nerve, and immune system function.
Plant cells are surrounded by:
a cell membrane and a cell wall |
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only a cell wall |
|
only a cell membrane |
|
neither a cell membrane nor a cell wall |
Animal cells are surrounded by a semipermeable membrane which allows for the transfer of water and oxygen to and from the cell. In plant cells, the cell membrane is surrounded by a somewhat rigid cell wall which provides the cell structure and support.
Which of the following temperatures is least like the others?
32°F |
|
absolute zero |
|
0K |
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-273°C |
Absolute zero is the coldest possible temperature in the universe. In the Kelvin scale, absolute zero is 0K and in the Celsius scale it is -273°C.
The four planets closest to the Sun are called terrestrial. What does terrestrial mean?
the planets have water |
|
the planets have magnetic fields |
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the planets are Earth-like |
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the planets have moons |
The four planets closest to the Sun (Mercury, Venus, Earth, and Mars) are called terrestrial (Earth-like) planets because, like the Earth, they're solid with inner metal cores covered by rocky surfaces.
Which of the following is the formula for power?
\(P = {w \over t}\) |
|
\(P = {\vec{w} \over t}\) |
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\(P = w t\) |
|
\(P = \vec{w}t\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).