Answer the following question given this paragraph: Often, a worker will need to change the concentration of a solution by changing the amount of solvent. Dilution is the addition of solvent, which decreases the concentration of the solute in the solution. Concentration is the removal of solvent, which increases the concentration of the solute in the solution. (Do not confuse the two uses of the word concentration here!) In both dilution and concentration, the amount of solute stays the same. This gives us a way to calculate what the new solution volume must be for the desired concentration of solute. From the definition of molarity,. Q: Concentration is the removal of solvent, which increases the concentration of what? Choices: - vapor - sodium - Water - solute A:
solute
Answer the following question given this paragraph: Most amphibians breathe with gills as larvae and with lungs as adults. Additional oxygen is absorbed through the skin in most species. The skin is kept moist by mucus, which is secreted by mucous glands. In some species, mucous glands also produce toxins, which help protect the amphibians from predators. The golden frog shown in Figure below is an example of a toxic amphibian. Q: What do most amphibians breathe with as larvae? Choices: - pores - lungs - nasal passages - gills A:
gills
Q: Answer the following question given this paragraph: A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. When force is applied to the inner axle, the ideal mechanical advantage is less than 1. When force is applied to the outer wheel, the ideal mechanical advantage is greater than 1. Q: What simple machine consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point? Choices: - pully - bloom and axle - spoke - wheel and axle A:
A: wheel and axle
Question: Answer the following question given this paragraph: An example of a mutualistic relationship is between herbivores (plant-eaters) and the bacteria that live in their intestines. The bacteria get a place to live. Meanwhile, the bacteria help the herbivore digest food. Both species benefit, so this is a mutualistic relationship. The clownfish and the sea anemones also have a mutualistic relationship. The clownfish protects the anemone from anemone-eating fish, and the stinging tentacles of the anemone protect the clownfish from predators ( Figure below ). Another example of this type of symbiotic relationship is the relationship between the plover bird and the African crocodile. The tiny blackbird acts as a toothpick for the fierce crocodile, and helps by removing tiny morsels of food that are stuck between the crocodile's teeth. These food remains are the source of food for the bird. Another example is between the ostrich and the zebra. The ostrich always moves with the herd of zebras since it has a poor sense of hearing and smell, whereas the zebra has very sharp senses. The ostrich has a keen sense of sight, which the zebra lacks. Hence, these two species depend on each other to warn one another of any nearby imposing dangers. Q: Herbivores and the bacteria that live in their intestines demonstrate a two-way beneficial relationship called what? Choices: - parasitism - pragmatism - syncretism - mutualism A:
Answer: mutualism
*Question*
Answer the following question given this paragraph: Steam rises from the cooling towers of this nuclear power plant. The steam is only harmless water vapor. Unlike a power plant that burns fossil fuel, a nuclear power plant doesn't release pollution into the air. That's because a nuclear power plant produces power by nuclear fission, a type of nuclear reaction. Q: What is harmless water vapor, for a powerplant? Choices: - wind - plasma - fog - steam A:
**Answer**
steam
*Question*
Answer the following question given this paragraph: Food Chains and Food Webs The term "food chain" is sometimes used metaphorically to describe human social situations. In this sense, food chains are thought of as a competition for survival, such as "who eats whom?" Someone eats and someone is eaten. Therefore, it is not surprising that in our competitive "dog-eat-dog" society, individuals who are considered successful are seen as being at the top of the food chain, consuming all others for their benefit, whereas the less successful are seen as being at the bottom. The scientific understanding of a food chain is more precise than in its everyday usage. In ecology, a food chain is a linear sequence of organisms through which nutrients and energy pass: primary producers, primary consumers, and higher-level consumers are used to describe ecosystem structure and dynamics. There is a single path through the chain. Each organism in a food chain occupies what is called a trophic level. Depending on their role as producers or consumers, species or groups of species can be assigned to various trophic levels. In many ecosystems, the bottom of the food chain consists of photosynthetic organisms (plants and/or phytoplankton), which are called primary producers. The organisms that consume the primary producers are herbivores: the primary consumers. Secondary consumers are usually carnivores that eat the primary consumers. Tertiary consumers are carnivores that eat other carnivores. Higher-level consumers feed on the next lower tropic levels, and so on, up to the organisms at the top of the food chain: the apex consumers. In the Lake Ontario food chain shown in Figure 46.4, the Chinook salmon is the apex consumer at the top of this food chain. Q: Secondary consumers are usually carnivores that eat what? Choices: - soil - plants - dead material - primary consumers A:
**Answer**
primary consumers