| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.79 |
| Score | 0% | 56% |
Which of the following is true about species groups?
an ecosystem is a biological population |
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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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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.
When two air masses meet and neither is displaced, what kind of front is present?
occluded |
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warm |
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cold |
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stationary |
When two air masses meet and neither is displaced, a stationary front is created. Stationary fronts often cause persistent cloudy wet weather.
Which of the following describes how a person's genes express themselves in physical characteristics?
DNA |
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chromotype |
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phenotype |
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genotype |
A person's genotype is their genetic makeup and includes both dominant and recessive alleles. Phenotype is how the genes express themselves in physical characteristics.
-40°F is how many °C?
\(-{40 \over 9}\) |
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\({40 \over 9}\) |
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-40 |
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-8 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)
Which of the following substances gives up positively charged hydrogen ions (H+) when dissolved in water?
base |
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solution |
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acid |
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alkaline |
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.