Answer the following question given this paragraph: Finally, air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in tiny air sacs called alveoli. Q: What is the name for the tiny air sacs at the end of bronchioles? Choices: - gills - vacuoles - ganglion - alveoli A:
alveoli
Answer the following question given this paragraph: HFCs are used as a replacement for CFCs. The molecular structure of HFC134a is shown in this ball-and-stick model. Q: Hfcs are used as a replacement for what? Choices: - nitrofluorocarbons - pollutants - gases - cfcs A:
cfcs
Q: Answer the following question given this paragraph: Q: What do we call heated groundwater that erupts from the ground under pressure? Choices: - aquifers - spas - volcanic eruptions - springs or geysers A:
A: springs or geysers
Question: Answer the following question given this paragraph: Terrestrial biomes , which are land-based, such as deserts and forests. Q: Deserts and forests are examples of what type of biome? Choices: - abundant - freshwater - acquatic - terrestrial A:
Answer: terrestrial
*Question*
Answer the following question given this paragraph: One way to keep iron from corroding is to keep it painted. The layer of paint prevents the water and oxygen necessary for rust formation from coming into contact with the iron. As long as the paint remains intact, the iron is protected from corrosion. Other strategies include alloying the iron with other metals. For example, stainless steel is mostly iron with a bit of chromium. The chromium tends to collect near the surface, where it forms an oxide layer that protects the iron. Zinc-plated or galvanized iron uses a different strategy. Zinc is more easily oxidized than iron because zinc has a lower reduction potential. Since zinc has a lower reduction potential, it is a more active metal. Thus, even if the zinc coating is scratched, the zinc will still oxidize before the iron. This suggests that this approach should work with other active metals. Another important way to protect metal is to make it the cathode in a galvanic cell. This is cathodic protection and can be used for metals other than just iron. For example, the rusting of underground iron storage tanks and pipes can be prevented or greatly reduced by connecting them to a more active metal such as zinc or magnesium (Figure 17.18). This is also used to protect the metal parts in water heaters. The more active metals (lower reduction potential) are called sacrificial anodes because as they get used up as they corrode (oxidize) at the anode. The metal being protected serves as the cathode, and so does not oxidize (corrode). When the anodes are properly monitored and periodically replaced, the useful lifetime of the iron storage tank can be greatly extended. Q: Zinc is more easily oxidized than iron because zinc has a lower reduction potential. since zinc has a lower reduction potential, it is a more what? Choices: - much metal - Trap metal - usually metal - active metal A:
**Answer**
active metal
Answer the following question given this paragraph: 9.3 Response to the Signal The initiation of a signaling pathway is a response to external stimuli. This response can take many different forms, including protein synthesis, a change in the cell's metabolism, cell growth, or even cell death. Many pathways influence the cell by initiating gene expression, and the methods utilized are quite numerous. Some pathways activate enzymes that interact with DNA transcription factors. Others modify proteins and induce them to change their location in the cell. Depending on the status of the organism, cells can respond by storing energy as glycogen or fat, or making it available in the form of glucose. A signal transduction pathway allows muscle cells to respond to immediate requirements for energy in the form of glucose. Cell growth is almost always stimulated by external signals called growth factors. Uncontrolled cell growth leads to cancer, and mutations in the genes encoding protein components of signaling pathways are often found in tumor cells. Programmed cell death, or apoptosis, is important for removing damaged or unnecessary cells. The use of cellular signaling to organize the dismantling of a cell ensures that harmful molecules from the cytoplasm are not released into the spaces between cells, as they are in uncontrolled death, necrosis. Apoptosis also ensures the efficient recycling of the components of the dead cell. Termination of the cellular signaling cascade is very important so that the response to a signal is appropriate in both timing and intensity. Degradation of signaling molecules and dephosphorylation of phosphorylated intermediates of the pathway by phosphatases are two ways to terminate signals within the cell. Q: Programmed cell death, which goes by what term, is important for removing damaged or unnecessary cells? Choices: - mytosis - synthesis - mutations - apoptosis A:
apoptosis