Answer the following question given this paragraph: The scientist must next form a conclusion. The scientist must study all of the data. What statement best explains the data? Did the experiment prove the hypothesis? Sometimes an experiment shows that a hypothesis is correct. Other times the data disproves the hypothesis. Sometimes it's not possible to tell. If there is no conclusion, the scientist may test the hypothesis again. This time he will use some different experiments. No matter what the experiment shows the scientist has learned something. Even a disproved hypothesis can lead to new questions. Q: If no conclusion is reached after an experiment, the scientist may retest what? Choices: - conclusion - materials - suggestions - hypothesis A:
hypothesis

Answer the following question given this paragraph: Diagram of a typical prokaryotic cell. Among other things, prokaryotic cells have a plasma membrane, cytoplasm, ribosomes, and DNA. Prokaryotes do not have membrane-bound organelles or a cell nucleus. Q: What are unique about prokaryotic cells' organelles? Choices: - no cell walls - no epidermis - only membrane - bound - not membrane-bound A:
not membrane-bound

Answer the following question given this paragraph: Gnathostomes: Jawed Fishes Gnathostomes or "jaw-mouths" are vertebrates that possess jaws. One of the most significant developments in early vertebrate evolution was the development of the jaw, which is a hinged structure attached to the cranium that allows an animal to grasp and tear its food. The evolution of jaws allowed early gnathostomes to exploit food resources that were unavailable to jawless fishes. Early gnathostomes also possessed two sets of paired fins, allowing the fishes to maneuver accurately. Pectoral fins are typically located on the anterior body, and pelvic fins on the posterior. Evolution of the jaw and paired fins permitted gnathostomes to expand from the sedentary suspension feeding of jawless fishes to become mobile predators. The ability of gnathostomes to exploit new nutrient sources likely is one reason that they replaced most jawless fishes during the Devonian period. Two early groups of gnathostomes were the acanthodians and placoderms (Figure 29.10), which arose in the late Silurian period and are now extinct. Most modern fishes are gnathostomes that belong to the clades Chondrichthyes and Osteichthyes. Q: What is the hinged structure attached to the cranium that allows an animal to grasp and tear its food? Choices: - tooth - neck - throat - jaw A:
jaw