Q&A Hero

Q: In the following reaction, galactose is a ________.galactose + glucose -> lactose + waterA) polysaccharideB) monomerC) polymerD) protein

Q: ________ is a hydroxyl group.A) -NH2B) -OHC) -COOHD) -H

Q: The following molecule is best described as a(n) ________.CH3-CH2-CH2-CH2A) proteinB) carbohydrateC) organic compoundD) inorganic compound

Q: A single carbon atom can form a maximum of ________ covalent bond(s). A) 0 B) 1 C) 2 D) 4

Q: People with lactose intolerance do not have enough ________. A) lactose B) lactase C) glucose D) fructose

Q: Please read the following scenario to answer the following questions. While radioactive isotopes are used in medicine to identify tumors and other diseases, they can also be used to treat diseases such as cancer. One method to treat cancerous tumors is to expose them to radiation, which can kill the cancerous cells and the tumor. In 2013, the U.S. Food and Drug Administration approved a new cancer treatment based on the radioactive isotope radium-223; this isotope has a half-life of 11.4 days. The radioactive drug, known as Xofigo, is injected into the patient's bloodstream and travels to certain regions of the body. Because it emits high-energy radiation over short distances, it can kill cancerous cells in the sites where it localizes. After the drug was injected into a person, the following data were collected regarding the amount of radiation measured in different organs in the person's body. Organ Measured radiation Brain 0.37 Liver 11.01 Bones 4262.60 Lungs 0.27 Urinary bladder 14.90 Using the table above, what kind of cancer do you think Xofigo is used to treat? A) liver cancer B) bone cancer C) brain cancer D) lung cancer

Q: Please read the following scenario to answer the following questions. While radioactive isotopes are used in medicine to identify tumors and other diseases, they can also be used to treat diseases such as cancer. One method to treat cancerous tumors is to expose them to radiation, which can kill the cancerous cells and the tumor. In 2013, the U.S. Food and Drug Administration approved a new cancer treatment based on the radioactive isotope radium-223; this isotope has a half-life of 11.4 days. The radioactive drug, known as Xofigo, is injected into the patient's bloodstream and travels to certain regions of the body. Because it emits high-energy radiation over short distances, it can kill cancerous cells in the sites where it localizes. After the drug was injected into a person, the following data were collected regarding the amount of radiation measured in different organs in the person's body. Organ Measured radiation Brain 0.37 Liver 11.01 Bones 4262.60 Lungs 0.27 Urinary bladder 14.90 A cancer patient receives an injection of the drug on March 1. Suppose that the patient must receive a second injection once the amount of the drug decreases to less than 6% in his or her body. On approximately what day should the cancer patient schedule an appointment to receive another injection? A) March 13 B) March 23 C) April 3 D) April 25

Q: Please read the following scenario to answer the following questions. While radioactive isotopes are used in medicine to identify tumors and other diseases, they can also be used to treat diseases such as cancer. One method to treat cancerous tumors is to expose them to radiation, which can kill the cancerous cells and the tumor. In 2013, the U.S. Food and Drug Administration approved a new cancer treatment based on the radioactive isotope radium-223; this isotope has a half-life of 11.4 days. The radioactive drug, known as Xofigo, is injected into the patient's bloodstream and travels to certain regions of the body. Because it emits high-energy radiation over short distances, it can kill cancerous cells in the sites where it localizes. After the drug was injected into a person, the following data were collected regarding the amount of radiation measured in different organs in the person's body. Organ Measured radiation Brain 0.37 Liver 11.01 Bones 4262.60 Lungs 0.27 Urinary bladder 14.90 Which of the following would be the best experiment to determine whether this drug is an effective treatment option for cancer patients? A) Give the drug to a single cancer patient and ask him how he feels several months later. B) Give the drug to a group of mice that have artificially induced tumors and measure whether their tumors are destroyed. C) Give the drug to a group of cancer patients and measure whether their tumors are destroyed. D) Give the drug to a single cancer patient and measure whether her tumor is destroyed.

Q: Please read the following scenario to answer the following questions. The last few miles of the marathon are the most difficult for Heather. Her hair is plastered to her head, sweat clings to her arms, and her legs feel as if they had nothing left. Heather grabs a cup of ice water. The ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. Then a breeze kicks up and she finally feels some coolness against her skin. Drops of sweat, once clinging to her forehead, now spill down, and Heather feels a stinging as the sweat flows into her eyes. When Heather grabbed the glass of ice water, the ice cubes were floating at the top. Why were the ice cubes floating in the water? A) Water can store large amounts of heat. B) Water can moderate temperatures through evaporative cooling. C) The density of water decreases when it freezes. D) Water has a cohesive nature.

Q: Please read the following scenario to answer the following questions. The last few miles of the marathon are the most difficult for Heather. Her hair is plastered to her head, sweat clings to her arms, and her legs feel as if they had nothing left. Heather grabs a cup of ice water. The ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. Then a breeze kicks up and she finally feels some coolness against her skin. Drops of sweat, once clinging to her forehead, now spill down, and Heather feels a stinging as the sweat flows into her eyes. Why did the sweat on Heather's forehead and arms form drops? A) because of the high salt content of sweat B) because of the cohesive nature of water C) because of the ability of water to moderate heat D) because of the high evaporative cooling effect of water

Q: The graph below shows data regarding radioactive decay of carbon-14. If decay continues to occur normally, how much C-14 will remain after 22,800 years? A) 25% B) 12.5% C) 6.25% D) 3.125%

Q: Examine the pH scale below. How does household bleach compare to household ammonia? A) Household ammonia has 100 times higher H+ concentration than household bleach. B) Household bleach has 10 times higher H+ concentration than household ammonia. C) Household bleach has 100 times higher H+ concentration than household ammonia. D) Household ammonia has 10 times higher H+ concentration than household bleach.

Q: All of the representations in the following figure EXCEPT one clearly show double bonds. Choose the exception. A) electron configuration B) structural formula C) space-filling model D) ball-and-stick model

Q: Examine the drawing of an atom below. The art is technically INCORRECT in that ________. A) neutrons are not located in the nucleus B) the electrons should be much farther away from the nucleus C) electrons do not orbit the nucleus D) electrons do not have a negative charge

Q: A fossil was found and determined by radiometric dating to be 11,400 years old. What is the ratio of carbon-14 to carbon-12 in this fossil compared to its environment? A) 12.5% B) 25% C) 37.5% D) 50%

Q: Which of the following is NOT a potential impact of ocean acidification? A) Decreasing H+ concentrations B) Coral bleaching C) Changes in metabolism of marine animals D) Increasing carbonic acid concentrations

Q: When a base is added to a buffered solution, the buffer will ________.A) donate OH -> ionsB) accept water moleculesC) donate H+ ionsD) form covalent bonds with the base

Q: What name is given to substances that resist changes in pH? A) buffers B) solutions C) acids D) bases

Q: Relative to a pH of 6, a pH of 4 has a ________. A) 200 times higher H+ concentration B) 100 times higher H+ concentration C) 20 times higher H+ concentration D) 100 times lower H+ concentration

Q: The lower the pH of a solution, the ________. A) greater the number of oxygen atoms B) more acidic the solution C) less toxic the solution D) higher the OH concentration

Q: A base ________. A) removes H2O molecules from a solution B) decreases the pH of a solution C) removes OH ions from a solution D) removes H+ ions from a solution

Q: Which of the following is an acid? A) NaOH B) NaCl C) HCl D) CH4

Q: Sugar dissolves when stirred into water. The sugar is the ________, the water is the ________, and the sweetened water is the ________. A) solution... solvent... solute B) solute... solvent... solution C) solvent... solute... solution D) solution... solute... solvent

Q: As water freezes, ________. A) its molecules move farther apart B) it cools the surrounding environment C) its hydrogen bonds break apart D) it loses its polarity

Q: Sweating cools your body by ________. A) cohesion B) radiation C) evaporative cooling D) hydrogen bonding

Q: Why (if you are careful) are you able to float a needle on the surface of water? A) Water has adhesive properties. B) The surface tension that is a result of water's cohesive properties makes this possible. C) The covalent bonds that hold a water molecule together make this possible. D) A single needle is less dense than water.

Q: The tendency of molecules of the same kind to stick together is called ________. A) bonding B) cohesion C) polarity D) adhesion

Q: Human body cells are approximately ________ water. A) 95"99% B) 25"35% C) 50"55% D) 70"95%

Q: What are the reactant(s) in the following chemical reaction?C6H12O6 + 6 H2O + 6 O2 -> 6 CO2 + 12 H2OA) CO2 and H2OB) C6H12O6, H2O, and O2C) O2 onlyD) C6H12O6, H2O, O2, CO2, and H2O

Q: How many oxygen atoms are in the products of the following reaction?C6H12O6 + 6 H2O + 6 O2 -> 6 CO2 + 12 H2OA) 18B) 6C) 12D) 24

Q: Adjacent water molecules are connected by the ________. A) sharing of electrons between the hydrogen of one water molecule and the oxygen of another water molecule B) electrical attraction between the hydrogen of one water molecule and the oxygen of another water molecule C) sharing of electrons between adjacent oxygen molecules D) electrical attraction between the hydrogen atoms of adjacent water molecules

Q: Adjacent water molecules are joined by ________ bonds. A) covalent only B) ionic C) polar and covalent D) hydrogen

Q: Why is water considered a polar molecule? A) The oxygen atom is found between the two hydrogen atoms. B) The oxygen atom attracts the hydrogen atoms. C) The oxygen end of the molecule has a slight negative charge, and the hydrogen end has a slight positive charge. D) Both hydrogen atoms are at one end of the molecule, and the oxygen atom is at the other end.

Q: The hydrogen and oxygen atoms of a water molecule are held together by ________ bonds. A) ionic B) hydrogen C) covalent D) polar

Q: Sulfur has an atomic number of 16. How many covalent bonds can sulfur form? A) 1 B) 2 C) 4 D) 0

Q: What name is given to bonds that involve the sharing of electrons? A) covalent B) hydrogen C) ionic D) polar

Q: In the following reaction, what type of bond is holding the two atoms together?K+Cl -> K+ + Cl -> KClA) hydrophilicB) ionicC) hydrophobicD) covalent

Q: The bond between oppositely charged ions is a(n) ________ bond. A) ionic B) polar C) hydrogen D) covalent

Q: An atom with an electrical charge is a(n) ________. A) isotope B) molecule C) ion D) compound

Q: How do radioactive isotopes differ from isotopes? A) Radioactive isotopes have more neutrons than do isotopes. B) Radioactive isotopes are stable; isotopes are unstable. C) Radioactive isotopes have fewer neutrons than do isotopes. D) Radioactive isotopes are unstable; isotopes are stable.

Q: Isotopes of an element have the same number of ________ and different numbers of ________. A) protons... neutrons B) protons... electrons C) neutrons... protons D) electrons... protons

Q: The way Earth moves about the sun is most like ________. A) a neutron and electron moving around a proton B) an electron moving around the nucleus of an atom C) a proton moving about an electron D) a neutron moving about a proton

Q: An uncharged atom of gold has an atomic number of 79 and an atomic mass of 197. This atom has ________ protons, ________ neutrons, and ________ electrons. A) 79... 118... 79 B) 118... 79... 118 C) 118... 276... 118 D) 79... 34... 79

Q: Beryllium's atomic mass is 9, and its atomic number is 4. How many neutrons are found in a beryllium atom? A) 9 B) 13 C) 4 D) 5

Q: An atom's ________ are found in its nucleus. A) neutrons and protons B) protons only C) neutrons and electrons D) electrons, protons, and neutrons

Q: All atoms of an element have the same number of ________. A) protons plus neutrons B) protons C) electrons D) neutrons

Q: In order to have a positive charge, an atom must have ________. A) more protons than electrons B) more electrons than protons C) more neutrons than protons D) more protons than neutrons

Q: Which of the following elements, essential to life, is a trace element? A) phosphorus B) carbon C) iodine D) calcium

Q: The four most common elements found in living organisms are ________. A) nitrogen, oxygen, phosphorus, and carbon B) carbon, oxygen, nitrogen, and hydrogen C) carbon, oxygen, potassium, and calcium D) oxygen, calcium, hydrogen, and carbon

Q: ________ is an example of an element. A) Water B) Carbon C) Glucose D) Salt

Q: How can radiation be controlled and safely used in medicine? A) Apply radiation throughout the body at uncontrolled doses. B) Apply radiation throughout the body at controlled doses. C) Apply radiation to specific parts of the body at uncontrolled doses. D) Apply radiation to specific parts of the body at controlled doses.

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. If the proportion of brightly colored male lizards increased steadily in future generations, this would ________. A) reject the original hypothesis B) be an example of evolution due to natural selection C) illustrate the relationship between structure and function D) demonstrate the flow of energy through a system

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. Which of the following conclusions can be drawn from the data? A) Dull-colored females are more likely to choose dull-colored males. B) Dull-colored males are likely to choose dull-colored females. C) Brightly colored males are stronger and more fertile than dull-colored males D) Females do not always choose brightly colored males.

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. "Male collared lizards show considerable color variation." This is a(n) ________. A) hypothesis B) conclusion C) observation D) result

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. Which of the following is the hypothesis of this case study? A) Male collared lizards exhibit color variation. B) Dull-colored males are less likely to be eaten by predators. C) A function of male coloration is to attract females. D) Males prefer brightly colored females.

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. Dull-colored males were used in this experiment to ________. A) serve as a comparison (control) group to the brightly colored males B) be sure that females could recognize the gender of the other lizards C) give the experiment more trials so that the data would be more persuasive D) be sure all females had a male with which they could mate

Q: Please use the following information to answer the following question(s). The collared lizard is a species found in the Desert Southwest. Male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. Your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. Your tentative explanation is that male color plays a role in attracting females for mating purposes. You predict that females will preferentially choose brightly colored males over dull-colored ones. To test your prediction, you observed the interactions of female collared lizards with their male counterparts. You selected males that were the same age and size, and that differed only in their coloration pattern. You placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. Out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. In three instances, the females did not mate with either type. Create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. On the y-axis, plot the frequency with which each type of male was chosen by females. Using this graph, answer the following questions. Is it reasonable to conclude (i.e., is it supported by the data) that female collared lizards prefer more brightly colored male lizards over dull-colored males? A) Yes, this conclusion is supported by the data. B) No, this conclusion is not supported by the data. C) The data do not clearly indicate a preference one way or the other. D) None of the above choices are correct.

Q: In the process of evolution by natural selection illustrated in the accompanying figure, which of the following is the mechanism or agent of natural selection? A) artificial selection B) selective breeding C) selective predation D) genetic drift

Q: Using the branching tree of life for bears depicted in the accompanying figure, choose from among the following bear species the one that is most distantly related to the sun bear. A) brown bear B) sloth bear C) spectacled bear D) giant panda

Q: Which of these results would you predict to occur if climate change results in increased warming global temperatures? A) Species competition will result in slower evolution in the tropics. B) The tree line (at which it is too cold for trees to grow) moves toward the north and south poles. C) Winters will be longer toward the poles. D) Land animals will suffer fewer consequences than marine animals.

Q: Information flow in biological systems is necessary for negative or regulative feedback to operate. Which of these examples does NOT involve flow of information providing feedback? A) Heat receptors send signals to promote sweating. B) Low blood sugar causes the liver to convert starch to sugar to be released in the blood. C) Drought kills many trees. D) Bacterial genes for breaking down lactose are activated in the presence of lactose.

Q: Regulation in biological systems depends on feedback, which is an example of information flow. When diabetes destroys insulin-producing cells, what information flow is disrupted? A) The body is unable to send signals that indicate the amount of sugar in the blood. B) Cells in the bladder are no longer able to send signals when the bladder fills. C) The pancreas is unable to produce enzymes to break down proteins. D) Appetite signals no longer regulate feeding.

Q: Antibiotic resistance evolves in bacteria when ________. A) the presence of antibiotics favors bacteria that already have genes for resistance B) farmers do not use enough antibiotics in animal feed C) the antibiotics create resistance genes in bacteria D) none of the above

Q: How do hypotheses differ from theories? A) Theories are more comprehensive than hypotheses. B) Theories must be testable; hypotheses do not need to be testable. C) Hypotheses are educated guesses, and theories are tentative explanations. D) Hypotheses are derived from experimentation, whereas theories are derived from observation.

Q: Which of the following are the proper components of the scientific method? A) experiment, conclusion, application B) question, observation, experiment, analysis, prediction C) observation, question, hypothesis, prediction, experiment, results, conclusion D) observation, question, opinion, conclusion, hypothesis

Q: You try to start your car, but it does not start. Which of these is a prediction? A) My car's battery is dead. B) If I recharge the battery, then my car will start. C) My car is too old to function properly. D) What is wrong with my car?

Q: You try to start your car, but it does not start. Which of these is a hypothesis? A) My car's battery is dead. B) If I recharge the battery, then my car will start. C) My car is too old to function properly. D) What is wrong with my car?

Q: A hypothesis is a(n) ________. A) tentative answer to a question B) guess C) observation D) theory

Q: Which of these would be a valid scientific hypothesis? A) Human history is determined by a series of supernatural events. B) Humans should help in the conservation of other animal species. C) Humans are controlled by forces beyond our understanding. D) Humans and bacteria share a common genetic code.

Q: Discovery science is primarily based on ________. A) hypothesis testing B) deduction C) experimentation D) observation

Q: Which of these statements is CORRECT? A) Scientific ideas are subjected to repeated testing. B) Science can be used to prove or disprove the idea that deities or spirits cause earthquakes and other natural disasters. C) Science does not require observations that other people can confirm. D) Only discovery science can lead to important conclusions about nature.

Q: What is the difference between discovery science and hypothesis-driven science? A) Discovery science "discovers" new knowledge, whereas hypothesis-driven science does not. B) Discovery science is based on deductive reasoning, whereas hypothesis-driven science is based on inductive reasoning. C) Discovery science is mostly about describing nature, whereas hypothesis-driven science tries to explain nature. D) Discovery science involves predictions about outcomes, whereas hypothesis-driven science involves tentative answers to specific questions.

Q: Science is ________. A) the inquiry-based effort to describe and explain nature B) the search for truth C) an organized set of principles for how to behave ethically and morally D) all of the above

Q: Over a span of two decades, scientists measured changes in the beak size of a population of Galpagos ground finches. This ________. A) provided evidence of natural selection in action B) is an example of artificial selection C) is an example of overproduction D) led Darwin to his theory of evolution through natural selection

Q: What accounts for the different breeds of domesticated dogs? A) overproduction B) natural selection C) competition D) artificial selection

Q: What does "adaptation" mean in an evolutionary context? A) the way an individual's body adjusts to its environment B) the accumulation of favorable variations in a population over time C) the ability of organisms to alter their appearance under changing environmental conditions D) all of the above

Q: Which of these is required for natural selection to occur? A) inheritance B) unequal reproductive success C) individual variation D) all of the above

Q: Which of these is most closely associated with Darwin? A) energy flow B) ecosystem structure C) the three domains of life D) natural selection

Q: The branch of biology that explains both the diversity and the unity of life is ________. A) evolution B) microbiology C) taxonomy D) genetics

Q: Members of the kingdom Plantae differ from members of the other kingdoms of Eukarya in that most members of the kingdom Plantae ________. A) are decomposers B) are unicellular C) are consumers D) produce their own food