| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
Which of the following is true about species groups?
a population is made up of a group of communities |
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an ecosystem is a biological population |
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a biome is a made up of a group of biospheres |
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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.
Which of the following substances gives up positively charged hydrogen ions (H+) when dissolved in water?
solution |
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acid |
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alkaline |
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base |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
In the heart, the __________ artery and vein manage blood flow to the lungs.
pulmonary |
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atrial |
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capillary |
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aorta |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.
Which of the following is not a vector quantity?
acceleration |
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momentum |
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mass |
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velocity |
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: \(\vec{v}\)
Acceleration is the rate of change of velocity per unit of time. Which of these is the formula for acceleration?
\(\vec{a} = { \vec{v} \over t }\) |
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\(\vec{a} = { \Delta \vec{v} \over t }\) |
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\(\vec{a} = { t \over \Delta \vec{v} }\) |
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\(\vec{a} = \Delta \vec{v} t \) |
Acceleration is the rate of change of velocity per unit of time. In physics, the delta symbol (\(\Delta\)) represents change so the formula for acceleration becomes \(\vec{a} = { \Delta \vec{v} \over t }\)