Answer the following question given this paragraph: Scientists often study the effects of environment on phenotype by studying identical twins. Identical twins have the same genes, so phenotypic differences between twins often have an environmental cause. Twin studies help understand the relative importance of environmental and genetic influences on individual traits and behaviors. Twins are a valuable source of information concerning the relationship between genes and environment. As monozygotic twins (identical) share their nuclear DNA, their polymorphisms , the nucleotide differences that make their DNA unique, are common to the two individuals. This means that any phenotypic variation, such as in height, intelligence, or any other measurable trait, is due to the environment. What is different about the experiences of the twins? What unique experiences might one twin have that the other twin did not have? By comparing phenotypes of hundreds of twins, researchers can understand the roles of genetics, shared environment and unique experiences in the formation and development of specific traits. Q: What is often the cause of phenotypic differences between identical twins? Choices: - natural selection - genetics - learned behavior - environment A:
environment
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Answer the following question given this paragraph: Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures below and below . You can see an animation showing how friction opposes motion at this URL:. Q: What force opposes a motion of a moving body? for example a car breaking on a road. Choices: - tension - vibration - thermal - friction A:
friction
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Answer the following question given this paragraph: Loud sounds can damage the hair cells lining the cochlea of the inner ear. Explain how this might affect the ability to hear sound. Q: What can damage the hair cells lining the cochlea of the inner ear? Choices: - amelodic sounds - unexpected sounds - wavering sounds - loud sounds A:
loud sounds
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Answer the following question given this paragraph: The Universe contains about a hundred billion galaxies. Q: Approximately how many galaxies are there in the universe? Choices: - an infinite number - a trillion - an octillion - about a hundred billion A:
about a hundred billion
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