Answer the following question given this paragraph: Water pollution comes from many sources. One of the biggest sources is runoff. Runoff picks up chemicals such as fertilizer from agricultural fields, lawns, and golf courses. It carries the chemicals to bodies of water. The added nutrients from fertilizer often cause excessive growth of algae, creating algal blooms (see Figure below ). The algae use up oxygen in the water so that other aquatic organisms cannot survive. This has occurred over large areas of the ocean, creating dead zones , where low oxygen levels have killed all ocean life. A very large dead zone exists in the Gulf of Mexico. Measures that can help prevent these problems include cutting down on fertilizer use. Preserving wetlands also helps because wetlands filter runoff. Q: What source of water pollution picks up chemicals from the ground with water and carries them to bodies of water? Choices: - fertilizer - erosion - sediment - runoff A:
runoff
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Answer the following question given this paragraph: Q: Dispersal occurs only on what time scale? Choices: - regular - conventional - developmental - evolutionary A:
evolutionary
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Answer the following question given this paragraph: The active transport of ions across the membrane causes an electrical gradient to build up across the plasma membrane. The number of positively charged ions outside the cell is greater than the number of positively charged ions in the cytosol. This results in a relatively negative charge on the inside of the membrane, and a positive charge on the outside. This difference in charges causes a voltage across the membrane. Voltage is electrical potential energy that is caused by a separation of opposite charges, in this case across the membrane. The voltage across a membrane is called membrane potential . Membrane potential is very important for the conduction of electrical impulses along nerve cells. Q: The active transport of ions across the membrane causes an electrical gradient to build up across the what? Choices: - colloidal membrane - components membrane - cells membrane - plasma membrane A:
plasma membrane
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Answer the following question given this paragraph: Some people are allergic to certain foods. Nuts and shellfish are common causes of food allergies. Other common causes of allergies include:. Q: Which waves have the longest wavelengths but the least energy in the atmosphere? Choices: - microwaves - channel waves - light waves - radio waves A:
radio waves
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