Q: In the presence of oxygen, hydrogen can interact to make what? Read this paragraph and choose the correct option from the provided answers: A pile of leaves slowly rots in the backyard. In the presence of oxygen, hydrogen can interact to make water. Gold can be stretched into very thin wires. Choices: - carbon - helium - acid - water A:
water
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Q: What do organisms use to store energy? Read this paragraph and choose the correct option from the provided answers: A lipid is an organic compound such as fat or oil. Organisms use lipids to store energy, but lipids have other important roles as well. Lipids consist of repeating units called fatty acids. Fatty acids are organic compounds that have the general formula CH 3 (CH 2 ) n COOH, where n usually ranges from 2 to 28 and is always an even number. There are two types of fatty acids: saturated fatty acids and unsaturated fatty acids. Choices: - tissues - proteins - metabolytes - lipids A:
lipids
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Q: Secondary consumers are usually carnivores that eat what? Read this paragraph and choose the correct option from the provided answers: 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. Choices: - soil - plants - dead material - primary consumers A:
primary consumers
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Q: Approximately how many billion years ago did our solar system begin? Read this paragraph and choose the correct option from the provided answers: Our solar system began about 5 billion years ago. The Sun, planets, and other solar system objects all formed at about the same time. The leading hypothesis for how they formed is called the nebular hypothesis . Choices: - four billion - three billion - nine billion - five billion A:
five billion
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