*Question*
Answer the following question given this paragraph: Penguins do not use their wings, known as flippers, to fly in the air. However, they do use them to move in the water. The theory of evolution suggests that penguins evolved to use their wings for a different purpose. A whale's pelvic bones, which were once attached to legs, are also vestigial structures. Whales are descended from land-dwelling ancestors that had legs. Q: What do you call structures like a whale's pelvic bones, which were once attached to legs, or wings that cannot be used for flight? Choices: - primitive - primordial - distinctive - vestigial A:
**Answer**
vestigial

*Question*
Answer the following question given this paragraph: Crustaceans, such as shrimp, lobsters, crabs, and crayfish, are the dominant aquatic arthropods. A few crustaceans are [3] terrestrial species like the pill bugs or sow bugs. The number of described crustacean species stands at about 47,000. Although the basic body plan in crustaceans is similar to the Hexapodahead, thorax, and abdomenthe head and thorax may be fused in some species to form a cephalothorax, which is covered by a plate called the carapace (Figure 15.22). The exoskeleton of many species is also infused with calcium carbonate, which makes it even stronger than in other arthropods. Crustaceans have an open circulatory system in which blood is pumped into the hemocoel by the dorsal heart. Most crustaceans typically have separate sexes, but some, like barnacles, may be hermaphroditic. Serial hermaphroditism, in which the gonad can switch from producing sperm to ova, is also found in some crustacean species. Larval stages are seen in the early development of many crustaceans. Most crustaceans are carnivorous, but detritivores and filter feeders are also common. Q: What subphylum, which includes crabs and crayfish, represents the dominant aquatic arthropods? Choices: - arachnids - sponges - invertebrates - crustaceans A:
**Answer**
crustaceans

*Question*
Answer the following question given this paragraph: Summary The concentration of a substance is the quantity of solute present in a given quantity of solution. Concentrations are usually expressed as molarity, the number of moles of solute in 1 L of solution. Solutions of known concentration can be prepared either by dissolving a known mass of solute in a solvent and diluting to a desired final volume or by diluting the appropriate volume of a more concentrated solution (a stock solution) to the desired final volume. Q: The concentration of a substance is the quantity of solute present in a given quantity of ___________? Choices: - structure - mixture - salutation - solution A:
**Answer**
solution

*Question*
Answer the following question given this paragraph: Depending on the surrounding conditions, normal matter usually exists as one of three phases: solid, liquid, or gas. A phase change is a physical process in which a substance goes from one phase to another. Usually the change occurs when adding or removing heat at a particular temperature, known as the melting point or the boiling point of the substance. The melting point is the temperature at which the substance goes from a solid to a liquid (or from a liquid to a solid). The boiling point is the temperature at which a substance goes from a liquid to a gas (or from a gas to a liquid). The nature of the phase change depends on the direction of the heat transfer. Heat going into a substance changes it from a solid to a liquid or a liquid to a gas. Removing heat from a substance changes a gas to a liquid or a liquid to a solid. Two key points are worth emphasizing. First, at a substance's melting point or boiling point, two phases can exist simultaneously. Take water (H2O) as an example. On the Saylor URL: http://www. saylor. org/books. Q: Depending on the surrounding conditions, normal matter usually exists as one of three phases: solid, liquid, or this? Choices: - fluid - crystal - ice - gas A:
**Answer**
gas