Answer the following question given this paragraph: Learn some applications of radioactivity. Radioactive isotopes have a variety of applications. Generally, however, they are useful because either we can detect their radioactivity or we can use the energy they release. Radioactive isotopes are effective tracers because their radioactivity is easy to detect. A tracer is a substance that can be used to follow the pathway of that substance through some structure. For instance, leaks in underground water pipes can be discovered by running some tritium-containing water through the pipes and then using a Geiger counter to locate any radioactive tritium subsequently present in the ground around the pipes. (Recall that tritium is a radioactive isotope of hydrogen. ) Tracers can also be used to follow the steps of a complex chemical reaction. After incorporating radioactive atoms into reactant molecules, scientists can track where the atoms go by following their radioactivity. One excellent example of this is the use of carbon-14 to determine the steps involved in. Q: What is the name for a substance that can be used to follow the pathway of that substance through some structure? Choices: - gel - tracker - solution - tracer A:
tracer
Answer the following question given this paragraph: Coevolution occurs when species evolve together. This often happens in species that have symbiotic relationships. Examples include flowering plants and their pollinators. Q: What is the term for species evolving together? Choices: - conjuration - interconnection - specmutation - coevolution A:
coevolution
Q: Answer the following question given this paragraph: polar, while others are strongly polar. Ionic bonds can be considered the ultimate in polarity, with electrons being transferred rather than shared. To judge the relative polarity of a covalent bond, chemists use electronegativity, which is a relative measure of how strongly an atom attracts electrons when it forms a covalent bond. There are various numerical scales for rating electronegativity. Figure 4.4 "Electronegativities of Various Elements" shows one of the most popularthe Pauling scale. The polarity of a covalent bond can be judged by determining the difference in the electronegativities of the two atoms making the bond. The greater the difference in electronegativities, the greater the imbalance of electron sharing in the bond. Although there are no hard and fast rules, the general rule is if the difference in electronegativities is less than about 0.4, the bond is considered nonpolar; if the difference is greater than 0.4, the bond is considered polar. If the difference in electronegativities is large enough (generally greater than about 1.8), the resulting compound is considered ionic rather than covalent. An electronegativity difference of zero, of course, indicates a nonpolar covalent bond. Q: What kind of bonds, where electrons are transferred rather than shared, are considered the ultimate in polarity? Choices: - covalent bonds - soluble bonds - magnetic bonds - ionic bonds A:
A: ionic bonds
Question: Answer the following question given this paragraph: Phytoplankton are "plant-like" plankton. Since they make food by photosynthesis, they live in the photic zone. Most are algae. Q: Which type of plankton make food via photosynthesis? Choices: - dinoflagellates - common plankton - zooplankton - phytoplankton A:
Answer: phytoplankton
*Question*
Answer the following question given this paragraph: 24.3 Lipid Metabolism Lipids are available to the body from three sources. They can be ingested in the diet, stored in the adipose tissue of the body, or synthesized in the liver. Fats ingested in the diet are digested in the small intestine. The triglycerides are broken down into monoglycerides and free fatty acids, then imported across the intestinal mucosa. Once across, the triglycerides are resynthesized and transported to the liver or adipose tissue. Fatty acids are oxidized through fatty acid or -oxidation into two-carbon acetyl CoA molecules, which can then enter the Krebs cycle to generate ATP. If excess acetyl CoA is created and overloads the capacity of the Krebs cycle, the acetyl CoA can be used to synthesize ketone bodies. When glucose is limited, ketone bodies can be oxidized and used for fuel. Excess acetyl CoA generated from excess glucose or carbohydrate ingestion can be used for fatty acid synthesis or lipogenesis. Acetyl CoA is used to create lipids, triglycerides, steroid hormones, cholesterol, and bile salts. Lipolysis is the breakdown of triglycerides into glycerol and fatty acids, making them easier for the body to process. Q: Lipids are available to the body from how many sources? Choices: - one - five - two - three A:
**Answer**
three
(Q).
Answer the following question given this paragraph: 4. Zeros that appear after all nonzero digits are called right-end zeros. Right-end zeros in a number that lacks a decimal point are not significant. A. 140 has two significant figures. Q: What do we call zeros that appear after nonzero digits? Choices: - left-end zeros - significant digits - placeholders - right-end zeros A:
(A).
right-end zeros