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23 Cards in this Set
- Front
- Back
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Pasteur's experiment provided conclusive evidence to reject the spontaneous generation hypothesis, which states that cells arise from nonliving material. As a consequence, his results supported the all-cells-from-cells hypothesis. Which element of Pasteur's experimental design was most important and why? |
His two treatments differed only in the shape of the flask, resulting in exposure of only one of the treatments to preexisting cells. |
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In Pasteur's experiment, the purpose of the swan neck on the flask was to: |
trap cells from the air before they reached the growth medium. |
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Pasteur's results showed that |
When growth medium is not contaminated by pre-existing cells, the growth medium remains sterile. |
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Imagine that researchers start with the same population of maize as shown in Figure 1.3, but instead of selecting individuals with the highest kernel protein content to be parents of each generation, they select individuals with the lowest kernel protein content instead. Which statement best describes how the average protein content of the population would differ from the starting population after 50 and 100 generations? |
It would be lower after both 50 and 100 generations |
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The data in Figure 1.7 show that: |
Most of the time, giraffes do not lift their necks fully when feeding.
Giraffes normally extend their necks to about 60% of the maximum height while feeding. |
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Which of the following statements is true about the testing of scientific hypotheses? |
Hypotheses may be tested by a combination of observation, measurement, and experimentation. |
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Could both the food competition hypothesis and the sexual competition hypothesis explain why giraffes have long necks? Why or why not? |
Yes. Long necks could be advantageous for more than one reason. |
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Explain how selection occurs during natural selection. |
Natural selection occurs when heritable variation in certain traits leads to improved success in reproduction. Natural selection acts on individuals. |
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Explain why researchers formulate a null hypothesis in addition to a hypothesis when designing an experimental study. |
A null hypothesis specifies what a researcher should observe when the hypothesis being tested isn't correct. |
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Some humans have heritable traits that make them resistant to infection by HIV.
In areas of the world where HIV infection rates are high, are human populations evolving? Explain your logic. |
Yes. The heritable traits that confer resistance to HIV should increase over time. |
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In biology, to what does the term fitness refer? |
An individual's ability to survive and reproduce. |
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What did Linnaeus's system of naming organisms ensure? |
Two different organisms never end up with the same genus and species name. |
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To answer questions about life, biologists use the scientific method, which involves hypotheses, predictions, and experiments. Which statement most accurately summarizes the relationship among these three elements? |
A hypothesis is a proposed answer to a tightly focused question; a prediction is a specific claim that follows from a hypothesis and that can be tested in an experiment. |
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What does it mean to say that a characteristic of an organism is heritable? |
The characteristic can be passed on to offspring. |
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The term evolution means that ______ change through time. |
populations |
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In the same portion of rRNA, you find the following sequences: Land Plants: AUAUCGAG Green Algae: AUAUGGAG Fungi: AUAUGGAC Based on these data, which statement most accurately summarizes the evolutionary relationships of these three types of organisms? |
Fungi are more closely related to green algae than to land plants. |
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Which of the following statements about the experiment shown in Figure 1.3 is supported by the data |
Over time, protein content of corn kernels increases more than it decreases. |
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Which of the following statements about natural selection is true? |
Natural selection favors individuals that reproduce more than others. |
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Which term describes a trait that increases an individual's ability to survive in a particular environment? |
Adaptation |
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Which term describes the ability of a trait to be passed on to offspring? |
Heritability |
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Which of the following organisms could be produced by artificial selection? |
A cow that produces a large quantity of milk.
A cow's ability to produce milk is a heritable trait that can be manipulated by artificial selection |
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Which pair of chickens should a farmer breed to produce larger chickens? |
Large hen, large rooster |
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A farmer wishes to develop a strain of high-yield corn that is also resistant to drought. He has the following individuals from the current year's crop: |
A and E |
