Answer the following question given this paragraph: A certain mineral may form in different colors. Figure below shows four samples of quartz, including one that is colorless and one that is purple. The purple color comes from a tiny amount of iron. The iron in quartz is a chemical impurity. Iron is not normally found in quartz. Many minerals are colored by chemical impurities. Other factors can also affect a mineral's color. Weathering changes the surface of a mineral. Because color alone is unreliable, geologists rarely identify a mineral just on its color. To identify most minerals, they use several properties. Q: Where does the purple color in quartz come from? Choices: - aluminum - dirt - bronze - iron A:
iron
Answer the following question given this paragraph: Abiotic features of rivers and streams vary along the length of the river or stream. Streams begin at a point of origin referred to as source water. The source water is usually cold, low in nutrients, and clear. The channel (the width of the river or stream) is narrower here than at any other place along the length of the river or stream. Headwater streams are of necessity at a higher elevation than the mouth of the river and often originate in regions with steep grades leading to higher flow rates than lower elevation stretches of the river. Faster-moving water and the short distance from its origin results in minimal silt levels in headwater streams; therefore, the water is clear. Photosynthesis here is mostly attributed to algae that are growing on rocks; the swift current inhibits the growth of phytoplankton. Photosynthesis may be further reduced by tree cover reaching over the narrow stream. This shading also keeps temperatures lower. An additional input of energy can come from leaves or other organic material that falls into a river or stream from the trees and other plants that border the water. When the leaves decompose, the organic material and nutrients in the leaves are returned to the water. The leaves also support a food chain of invertebrates that eat them and are in turn eaten by predatory invertebrates and fish. Plants and animals have adapted to this fast-moving water. For instance, leeches (phylum Annelida) have elongated bodies and suckers on both ends. These suckers attach to the substrate, keeping the leech anchored in place. In temperate regions, freshwater trout species (phylum Chordata) may be an important predator in these fast-moving and colder river and streams. Q: In headwater streams, what plant process is mostly attributed to algae that are growing on rocks? Choices: - mitosis - symbiosis - reproduction - photosynthesis A:
photosynthesis
Q: Answer the following question given this paragraph: Climate conditions in a small area may be different from those of the surroundings. The climate of the small area is called a microclimate . The microclimate of a valley may be cool relative to its surroundings since cold air sinks. The ground surface may be hotter or colder than the air a few feet above it. This is because rock and soil gain and lose heat readily. Different sides of a mountain will have different microclimates. In the Northern Hemisphere, a south-facing slope receives more solar energy than a north-facing slope. Each side supports different amounts and types of vegetation. Q: What is the climate of a small area called? Choices: - ecosystem - biome - microevolution - microclimate A:
A: microclimate
Question: Answer the following question given this paragraph: The other ammonium ions are changed into nitrogen gas by denitrifying bacteria. Q: The other ammonium ions are changed into nitrogen gas by what? Choices: - fluctuations bacteria - fungi - accompanying bacteria - denitrifying bacteria A:
Answer: denitrifying bacteria
*Question*
Answer the following question given this paragraph: Abiotic factors are the nonliving parts of ecosystems. They include air, soil, and other things organisms need. They determine which organisms and how many of them can live in an ecosystem. Q: What are the nonliving parts of ecosystems like soil and air called? Choices: - exemplified factors - irrelevant factors - inorganic factors - abiotic factors A:
**Answer**
abiotic factors
Q: Answer the following question given this paragraph: The presence of solute particles has the opposite effect on the freezing point of a solution. When a solution freezes, only the solvent particles come together to form a solid phase, and the presence of solute particles interferes with that process. Therefore, for the liquid solvent to freeze, more energy must be removed from the solution, which lowers the temperature. Thus, solutions have lower freezing points than pure solvents do. This phenomenon is called freezing point depression. For every mole of particles in a liter of water, the freezing point decreases by about 1.9C. Both boiling point elevation and freezing point depression have practical uses. For example, solutions of water and ethylene glycol (C2H6O2) are used as coolants in automobile engines because the boiling point of such a solution is greater than 100C, the normal boiling point of water. In winter, salts like NaCl and CaCl2 are sprinkled on the ground to melt ice or keep ice from forming on roads and sidewalks. This is because the solution made by dissolving sodium chloride or calcium chloride in water has a lower freezing point than pure water, so the formation of ice is inhibited. Q: When a solution freezes, only what particles come together to form a solid phase, while the presence of solute particles interferes with that process? Choices: - pigment - hydrogen - diluent - solvent A:
A: solvent