Answer the following question given this paragraph: Globular clusters are spherical groups of old stars held tightly together by gravity. Q: What is the name for spherical groups of old stars held tightly together by gravity? Choices: - nebula - elliptical clusters - dark matter - globular clusters A:
globular clusters
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Answer the following question given this paragraph: Herbivory has been used by seed plants for their own benefit in a display of mutualistic relationships. The dispersal of fruit by animals is the most striking example. The plant offers to the herbivore a nutritious source of food in return for spreading the plant's genetic material to a wider area. An extreme example of collaboration between an animal and a plant is the case of acacia trees and ants. The trees support the insects with shelter and food. In return, ants discourage herbivores, both invertebrates and vertebrates, by stinging and attacking leaf-eating insects. Q: How do seed plants benefit from herbivores? Choices: - radiation of seeds - consumption of seeds - rainfall of seeds - dispersal of seeds A:
dispersal of seeds
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Answer the following question given this paragraph: Biodiversity is a measurement of the amount of variation of the species in a given area. More specifically, biodiversity can be defined as the variety of life and its processes, including the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur. Q: What is a measurement of the amount of variation of the species in a given area called? Choices: - ecosystem - population - degradation - biodiversity A:
biodiversity
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Answer the following question given this paragraph: Receiving Electromagnetic Waves Electromagnetic waves carry energy away from their source, similar to a sound wave carrying energy away from a standing wave on a guitar string. An antenna for receiving EM signals works in reverse. And like antennas that produce EM waves, receiver antennas are specially designed to resonate at particular frequencies. An incoming electromagnetic wave accelerates electrons in the antenna, setting up a standing wave. If the radio or TV is switched on, electrical components pick up and amplify the signal formed by the accelerating electrons. The signal is then converted to audio and/or video format. Sometimes big receiver dishes are used to focus the signal onto an antenna. In fact, charges radiate whenever they are accelerated. When designing circuits, we often assume that energy does not quickly escape AC circuits, and mostly this is true. A broadcast antenna is specially designed to enhance the rate of electromagnetic radiation, and shielding is necessary to keep the radiation close to zero. Some familiar phenomena are based on the production of electromagnetic waves by varying currents. Your microwave oven, for example, sends electromagnetic waves, called microwaves, from a concealed antenna that has an oscillating current imposed on it. Q: What happens to charges whenever they are accelerated? Choices: - they fuse - they darken - they die - they radiate A:
they radiate
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