What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. NADH Correct Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. e. monomers Correct When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? Choose one answer. c. the cell will become turgid Correct When pairs of homologous chromosomes separate during anaphase I, Choose one answer. a. the sister chromatids remain attached to one another. Correct Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt BBtt will have black fur and long tails? Choose one answer. d. 1/2 Correct Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. d. No groups have such higher frequency Correct The body is capable of catabolizing many substances as sources of energy. Which of the followingwould be used as an energy source only after the depletion of other sources? Choose one answer. d. protein in muscle cells Correct Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that Choose one answer. c. None of the other answer choices correctly describes these solutions. Correct A gene's location along a chromosome is known as which of the following? Choose one answer. a. Locus Correct Which of the following is a nutritional monomer that can be transported in the blood? Choose one answer. b. fatty acid Correct Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. e. kidneys of vertebrates Correct Which of these stimulate the production of red blood cells? Choose one answer. d. erythropoietin Correct In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. b. proteins and nucleic acids. Correct Independent assortment of chromosomes is a result of Choose one answer. a. the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. Correct Which of the following is an example of countercurrent exchange? Choose one answer. d. the flow of water across the gills of a fish and that of blood within those gills Correct SRY is best described in which of the following ways? Choose one answer. c. A gene region present on the Y chromosome that triggers male development Correct

Which of the following is an example of qualitative data? Choose one answer. e. The fish swam in a zig-zag motion. Correct What does a frequency of recombination of 50% indicate? Choose one answer. e. The two genes are likely to be located on different chromosomes. Correct You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample? Choose one answer. a. 6.02 1024 Correct Which of the following span the phospholipids bilayer, usually a number of times? Choose one answer. a. transmembrane proteins Correct Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct Individuals whose diet consists primarily of corn would likely become Choose one answer. d. malnourished. Correct Which of the following is true for all exergonic reactions? Choose one answer. b. The reactions are nonspontaneous. Incorrect Where are the molecules of the electron transport chain found in plant cells? Choose one answer. b. thylakoid membranes of chloroplasts Correct DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run? Choose one answer. e. None of the individual insects should have possessed genomes that made them resistant to DDT. Correct Choose one answer. d. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct An organism has a relatively large number of Hox genes in its genome. Which of the following is not true of this organism? Choose one answer. b. It must have multiple paired appendages along the length of its body. Correct A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. blue and violet Correct Birds secrete uric acid as their nitrogenous waste because uric acid Choose one answer b. requires little water for nitrogenous waste disposal which is conducive to the function of flight in terms of weight. Correct When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, -S Correct This is the shortest part of the cell cycle: Choose one answer. b. M Correct

Which of the following takes place as an ice cube cools a drink? Choose one answer. a. Kinetic energy in the drink decreases. Correct What was the prevailing notion prior to the time of Lyell and Darwin? Choose one answer. b. Earth is a few thousand years old, and populations are unchanging. Correct Which of the following is not a theme that unifies biology? Choose one answer. c. reductionism Correct Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants Choose one answer. e. a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. Correct Which of the following is present in a prokaryotic cell? Choose one answer. d. ribosome Correct All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. c. Characteristics of organisms are inherited as genes on chromosomes. Correct The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via which of the following? Choose one answer. e. integrins Correct Which of these naturalists synthesized a concept of natural selection independently of Darwin? Choose one answer. c. Alfred Wallace Correct Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur? Choose one answer. b. in photosynthesizing cells in dark periods and in other tissues all the time Correct Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited? Choose one answer. b. Nervous and muscular systems Correct Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. c. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct In which of the following would there be the greatest need for osmoregulation? Choose one answer. e. a terrestrial animal such as a snake Correct Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. b. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct Which of the following enzymes works most effectively at a very low pH? Choose one answer. c. pepsin Correct What is the main nitrogenous waste excreted by birds? Choose one answer. c. uric acid Correct

Which of these is a statement that Darwin would have rejected? Choose one answer. d. The smallest entity that can evolve is an individual organism. Correct During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. c. FADH2 Correct Where and from what compound(s) is urea produced? Choose one answer. c. liver from NH3 and CO2 Correct Large proteins such as albumin remain in capillaries rather than diffusing out. Which of the following does this cause? Choose one answer. a. creation of an osmotic pressure difference across capillary walls Correct The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. neither photosynthesis nor respiration. Correct Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be Choose one answer. b. to test for liberation of O2 in the light. Correct Life is diverse. How many species are estimated to be presently on the earth? Choose one answer. d. 1,800,000 Correct A molecule that is phosphorylated Choose one answer. c. has an increased chemical reactivity; it is primed to do cellular work. Correct What does the chemiosmotic process in chloroplasts involve? Choose one answer. a. establishment of a proton gradient Correct Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? Choose one answer. a. compartmentalization of enzymes into defined organelles Correct A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis? Choose one answer. b. The animal has a very long distance between heart and brain. Correct For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. d. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct The average resting stroke volume of the heart is 70 mL and it beats ~72 times per minute. This would result in which cardiac output? Choose one answer. e. 5 L/minute Correct Which of the following hydrocarbons has a double bond in its carbon skeleton? Choose one answer. b. C2H4 Correct The average birth weight for human babies is about 3 kg. Which of the following terms best describes this? Choose one answer. a. stabilizing selection Correct Where and from what compound(s) is urea produced? Choose one answer. d. liver from NH3 and CO2 Correct Which of the following statements correctly defines a kilocalorie? Choose one answer.

c. the amount of heat required to raise the temperature of 1 kg of water by 1C Correct In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve? Choose one answer. d. It increases the surface for oxidative phosphoryation. Correct Which of these speed up heart rate? Choose one answer. a. epinephrine Correct Cyanide acts as a mitochondrial poison by blocking the final step in the electron transport chain. What will happen to human red blood cells if they are placed in an isotonic solution containing cyanide? Choose one answer. d. The cells will probably be unaffected. Correct The bonds that are broken when water vaporizes are Choose one answer. a. hydrogen bonds between water molecules. Correct Average blood pressure is lowest in which structure(s)? Choose one answer. d. venae cavae Correct Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. c. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. d. rabbits, horses, and herbivorous bears Correct Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. e. light is absorbed and funneled to reaction-center chlorophyll a. Correct Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? Choose one answer. e. The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. Correct Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. e. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct Which of the following statements is true of mammals? Choose one answer. d. The epiglottis prevents food from entering the trachea. Correct The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as Choose one answer. c. discovery science. Correct Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase? Choose one answer. d. It is an allosteric enzyme. Correct Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. Choose one answer. b. 2 ? 4 ? 1 ? 3 Correct Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend?

Choose one answer. d. the ability of an enzyme to form a template for holding and joining molecules Correct Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct Photorespiration lowers the efficiency of photosynthesis by preventing the formation of Choose one answer. d. 3-phosphoglycerate molecules Correct Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. b. gain of water through food Correct Women with Turner syndrome have a genotype characterized as which of the following? Choose one answer. a. A karyotype of 45, X Correct Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. metaphase Correct A type of protein critical to all cells is organic catalysts called Choose one answer. d. enzymes. Correct Unlike an earthworm's metanephridia, a mammalian nephron Choose one answer. c. receives filtrate from blood instead of coelomic fluid. Correct Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply? Choose one answer. a. Photosystem I must be more ancestral. Correct Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. Answer: True False Incorrect Microbial symbionts are especially important for nutritional support in which of the following? Choose one answer b. herbivores and omnivores Correct Which of the following ionizes completely in solution and is considered to be a strong acid? Choose one answer. a. HCl Correct A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? Choose one answer. c. HT Correct Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. d. loop of Henle Correct When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of Choose one answer. b. negative feedback. Correct Grana, thylakoids, and stroma are all components found in Choose one answer.

d. chloroplasts. Correct In negative pressure breathing, inhalation results from Choose one answer. e. contracting the diaphragm. Correct Which of the following are capable of converting light energy to chemical energy? Choose one answer. b. chloroplasts Correct A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? Choose one answer. c. Its gametes must have 23 chromosomes. Correct When muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by Choose one answer. b. increase in potassium ions. Correct Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. b. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that to keep the frogs in a smoke-filled environment for defined periods would result in lung cancer in the animals. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly) they knew that a more likely outcome would be which of the following? Choose one answer. c. skin cancer Correct A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. e. the activation energy barrier for this reaction cannot be surmounted. Correct During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from? Choose one answer. d. molecular oxygen (O2) Correct For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. a. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]? Choose one answer. b. seawater at pH 8 Correct Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not Choose one answer. b. perform controlled, precise reproduction. Correct Asexual reproduction results in identical offspring unless which of the following occurs? Choose one answer. c. Mutation Correct If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? Choose one answer. b. metaphase Correct If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? Choose one answer.

e. n + 1; n + 1; n - 1; n - 1 Correct The human X and Y chromosomes Choose one answer. c. include genes that determine an individual's sex. Correct Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? Choose one answer. d. acetyl CoA Correct What is the primary function of the Calvin cycle? Choose one answer. d. synthesize simple sugars from carbon dioxide Correct Which describes the ABO blood group system? Choose one answer. b. Multiple alleles Correct How can one increase the rate of a chemical reaction? Choose one answer. e. Add a catalyst. Correct In which group of animals would you expect to find a relatively long cecum? Choose one answer. c. herbivores Correct In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald? Choose one answer. e. 75% Correct Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, whereas a different process that could have potentially contributed to the cluster's presence on more than one chromosome was __________. I. binary fission II. translation III. gene duplication IV. non-disjunction V. transcription Choose one answer. b. III, IV Correct When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes Choose one answer. d. oxidized. Correct The theory of evolution is most accurately described as Choose one answer. b. an overarching explanation, supported by much evidence, for how populations change over time. Correct Countercurrent exchange in the fish gill helps to maximize which of the following? Choose one answer. d. diffusion Correct A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. c. domain Eukarya, kingdom Fungi Correct

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? Choose one answer. c. gap junctions Correct Most CO2 from catabolism is released during Choose one answer. a. the citric acid cycle. Correct The body is capable of catabolizing many substances as sources of energy. Which of the followingwould be used as an energy source only after the depletion of other sources? Choose one answer. a. protein in muscle cells Correct Homologous chromosomes synapse and crossing over occurs. Choose one answer. d. The statement is true for meiosis I only. Correct Altering which of the following levels of structural organization could change the function of a protein? Choose one answer. a. all of the above Correct Familial hypercholesterolemia is characterized by which of the following? Choose one answer. c. defective LDL receptors on the cell membranes Correct Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited? Choose one answer. d. Nervous and muscular systems Correct Approximately what percentage of the energy of glucose (C6H12O6) is transferred to storage in ATP as a result of the complete oxidation of glucose to CO2 and water in cellular respiration? Choose one answer. e. 40% Correct SRY is best described in which of the following ways? Choose one answer. b. A gene region present on the Y chromosome that triggers male development Correct Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes increase the rate of a reaction. Correct When does the synaptonemal complex disappear? Choose one answer. c. Late prophase of meiosis I Correct Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? Choose one answer. a. the synthesis of ATP Correct Which of the following nitrogenous wastes requires hardly any water for its excretion? Choose one answer. d. uric acid Correct Protists and bacteria are grouped into different domains because Choose one answer. e. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? Choose one answer

d. 80 mm Hg Correct Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. c. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct The frequency of heterozygosity for the sickle cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? Choose one answer. d. Darwin's explanation of natural selection Correct Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. b. they cannot be manufactured by the organism. Correct Which of the following best describes enthalpy (H)? Choose one answer. c. the heat content of a chemical system Correct Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. d. nervous system, brain, nervous tissue, nerve cell Correct What is the substrate of salivary amylase? Choose one answer. c. starch Correct After ingestion, the first type of macromolecule to be worked on by enzymes in the human digestive system is Choose one answer. a. carbohydrate. Correct Organic chemistry is a science based on the study of Choose one answer. b. carbon compounds. Correct When you have a severe fever, what may be a grave consequence if this is not controlled? Choose one answer. e. change in the folding of enzymes Correct When a disease is said to have a multifactorial basis, it means that Choose one answer. c. both genetic and environmental factors contribute to the disease. Correct Cell membranes are asymmetrical. Which of the following is a most likely explanation? Choose one answer. e. Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. Correct Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? Choose one answer. b. ATP and NADPH Correct A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? Choose one answer. c. Archaea Correct Which of the following is not a normal response to increased blood osmolarity in humans? Choose one answer. a. production of more dilute urine Correct Which of the following is measured by an electrocardiogram? Choose one answer. a. the spread of impulses from the SA node Correct

In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. b. harvest photons and transfer light energy to the reaction-center chlorophyll Correct Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. H2O ? NADPH ? Calvin cycle Correct Which of the following takes place as an ice cube cools a drink? Choose one answer. c. Kinetic energy in the drink decreases. Correct Which of the following enzymes works most effectively at a very low pH? Choose one answer. a. salivary amylase Incorrect b. trypsin Incorrect c. pancreatic lipase Incorrect d. pancreatic amylase Incorrect e. pepsin Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? Choose one answer. a. the high surface tension of water Incorrect b. the release of heat by the breaking of hydrogen bonds Incorrect c. reactions with other atmospheric compounds Incorrect d. the release of heat by the formation of hydrogen bonds Correct e. the change in density when it condenses to form a liquid or solid Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following is reflective of the phrase "the whole is greater than the sum of its parts"? Choose one answer. a. reductionism Incorrect b. feedback regulations Incorrect c. emergent properties Correct d. natural selection Incorrect e. high-throughput technology Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be Choose one answer. a. 56. Incorrect b. 16. Incorrect c. 12. Incorrect d. 14. Incorrect e. 28. Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is an example of polygenic inheritance? Choose one answer. a. Huntington's disease in humans Incorrect b. White and purple flower color in peas Incorrect c. Skin pigmentation in humans Correct d. Pink flowers in snapdragons Incorrect e. The ABO blood groups in humans Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The active site of an enzyme is the region that

Choose one answer. a. binds the products of the catalytic reaction. Incorrect b. binds allosteric regulators of the enzyme. Incorrect c. is inhibited by the presence of a coenzyme or a cofactor. Incorrect d. is involved in the catalytic reaction of the enzyme. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction Choose one answer. a. loses electrons and gains energy. Incorrect b. neither gains nor loses electrons, but gains or loses energy. Incorrect c. loses electrons and loses energy. Correct d. gains electrons and loses energy. Incorrect e. gains electrons and gains energy. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Asexual reproduction and sexual reproduction differ in all but which of the following ways? Choose one answer. a. Individuals reproducing asexually transmit 100% of their genes to their progeny, whereas individuals reproducing sexually transmit only 50%. Incorrect b. Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized only by plants and animals. Correct c. Asexual reproduction involves a single parent, whereas sexual reproduction involves two. Incorrect d. Asexual reproduction requires only mitosis, whereas sexual reproduction always involves meiosis. Incorrect e. Asexual reproduction produces offspring that are genetically identical to the parents, whereas sexual reproduction gives rise to genetically distinct offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect b. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct c. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect d. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect e. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. vasa recta Correct b. proximal tubule Incorrect c. loop of Henle Incorrect d. Bowman's capsule Incorrect e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Why is it important to know what microscopy method was used to prepare the images you wish to study? Choose one answer. a. so that you can judge whether the images you are seeing are of cells or of organelles Incorrect b. so that you can interpret the correct biochemical process that is occurring Incorrect c. so that you can decide whether the image is actually of the size described Incorrect d. so that you can make a judgment about the likelihood of artifacts having been introduced in the preparation Correct e. so that you can know whether to view the image in color or not Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 The average resting stroke volume of the heart is 70 mL and it beats ~72 times per minute. This would result in which cardiac output? Choose one answer.

a. 5 L/minute Correct b. 500 L/minute Incorrect c. 0.5 L/minute Incorrect d. 50 L/minute Incorrect e. 504 mL/minute Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called Choose one answer. a. ATPases. Incorrect b. proton pumps. Incorrect c. centrioles. Incorrect d. kinetochores. Incorrect e. cyclins. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Which of these is a statement that Darwin would have rejected? Choose one answer. a. Individuals can acquire new characteristics as they respond to new environments or situations. Incorrect b. Inherited variation in a population is a necessary precondition for natural selection to operate. Incorrect c. Natural populations tend to produce more offspring than the environment can support. Incorrect d. Environmental change plays a role in evolution. Incorrect e. The smallest entity that can evolve is an individual organism. Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following statements is representative of the second law of thermodynamics? Choose one answer. a. Cells require a constant input of energy to maintain their high level of organization. Correct b. Conversion of energy from one form to another is always accompanied by some gain of free energy. Incorrect c. Every energy transformation by a cell decreases the entropy of the universe. Incorrect d. Without an input of energy, organisms would tend toward decreasing entropy. Incorrect e. Heat represents a form of energy that can be used by most organisms to do work. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population's gene pool at a locus that had formerly been fixed? Choose one answer. a. Average number of loci Incorrect b. Nucleotide variability Incorrect c. Average heterozygosity Correct d. Geographic variability Incorrect Correct Marks for this submission: 1/1. Question 54 Marks: 1 The advantage of excreting wastes as urea rather than as ammonia is that Choose one answer. a. urea does not affect the osmolar gradient. Incorrect b. urea requires more water for excretion than ammonia. Incorrect c. less nitrogen is removed from the body. Incorrect d. urea can be exchanged for Na+. Incorrect e. urea is less toxic than ammonia. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? Choose one answer. a. The sizes of the structures in adult members of both species are similar in size. Incorrect b. The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. Correct

c. Both species are well adapted to their particular environments. Incorrect d. Both species reproduce sexually. Incorrect e. The two species live at great distance from each other. Incorrect Correct Marks for this submission: 1/1. Question 56 Marks: 1 Where and from what compound(s) is urea produced? Choose one answer. a. kidneys from glucose Incorrect b. kidneys from glycerol and fatty acids Incorrect c. liver from glycogen Incorrect d. liver from NH3 and CO2 Correct e. bladder from uric acid and H2O Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. fermentation and chemiosmosis Incorrect b. glycolysis and fermentation Correct c. citric acid cycle Incorrect d. oxidative phosphorylation Incorrect e. oxidation of pyruvate to acetyl CoA Incorrect Correct Marks for this submission: 1/1. Question 58 Marks: 1 Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? Choose one answer. a. centrosome Correct b. chromatid Incorrect c. centromere Incorrect d. kinetochore Incorrect e. centriole Incorrect Correct Marks for this submission: 1/1. Question 59 Marks: 1 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? Choose one answer. a. a change in the shape of the nucleus Correct b. the inability of the cell to withstand enzymatic digestion Incorrect c. the loss of all nuclear function Incorrect d. failure of chromosomes to carry genetic information Incorrect e. inability of the nucleus to keep out destructive chemicals Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? Choose one answer. a. The two strands of the double helix would separate. Incorrect b. The purines would be separated from the deoxyribose sugars. Incorrect c. The phosphodiester linkages between deoxyribose sugars would be broken. Correct d. The pyrimidines would be separated from the deoxyribose sugars. Incorrect e. All bases would be separated from the deoxyribose sugars. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 4 Started on Saturday, January 17, 2009, 08:29 AM Completed on Saturday, January 17, 2009, 08:31 AM Time taken 1 min 52 secs Raw score 7/60 (12%)

Grade out of a maximum of Question 1 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. birds. Incorrect b. desert tortoises. Incorrect c. kangaroo rats. Correct d. humans. Incorrect e. frogs. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Physical anthropologists locating the jaw bones of previously unknown vertebrate animal fossils are often able to assess the animal's diet especially because of clues from which of the following? Choose one answer. a. the prevalence of specific kinds of teeth Correct b. whether the mouth is the most anterior structure Incorrect c. the position of muscle attachment sites Incorrect d. the size of the mouth opening Incorrect e. the evidence of food molecules still present Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 The ATP made during fermentation is generated by which of the following? Choose one answer. a. oxidative phosphorylation Incorrect b. the electron transport chain Incorrect c. chemiosmosis Incorrect d. aerobic respiration Incorrect e. substrate-level phosphorylation Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 How can one increase the rate of a chemical reaction? Choose one answer. a. Increase the entropy of the reactants. Incorrect b. Add a catalyst. Correct c. Cool the reactants. Incorrect d. Decrease the concentration of the reactants. Incorrect e. Increase the activation energy needed. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following statements is a logical consequence of the second law of thermodynamics? Choose one answer. a. Every energy transfer requires activation energy from the environment. Incorrect b. If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. Incorrect c. Every chemical reaction must increase the total entropy of the universe. Correct d. If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. Incorrect e. Energy can be transferred or transformed, but it cannot be created or destroyed. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it Choose one answer. a. would function only as a base because of the amino group. Incorrect b. would function as neither an acid nor a base. Incorrect c. would function as both an acid and a base. Correct d. would function only as an acid because of the carboxyl group. Incorrect e. is impossible to determine how it would function. Incorrect Incorrect Marks for this submission: 0/1. Question 7

Marks: 1 In what way were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth? Choose one answer. a. Only early Earth had an oxidizing atmosphere. Incorrect b. Less ultraviolet radiation penetrated Earth's early atmosphere. Incorrect c. Only early Earth had water vapor in its atmosphere. Incorrect d. Earth's early atmosphere had significant quantities of ozone. Incorrect e. Only early Earth was intensely bombarded by large space debris. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. can be made by the animal's body from other substances. Correct b. must be ingested in the diet. Incorrect c. is less important than an essential amino acid. Incorrect d. is not used by the animal in biosynthesis. Incorrect e. is not found in many proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The residual volume of the lungs decreases. Incorrect b. The epiglottis closes. Incorrect c. The rib cage expands. Incorrect d. The volume of the thoracic cavity decreases. Correct e. The diaphragm contracts. Incorrect Correct Marks for this submission: 1/1. Question 10 Marks: 1 Air rushes into the lungs of humans during inhalation because Choose one answer. a. pulmonary muscles contract and pull on the outer surface of the lungs. Incorrect b. pressure in the alveoli increases. Incorrect c. gas flows from a region of lower pressure to a region of higher pressure. Incorrect d. a positive respiratory pressure is created when the diaphragm relaxes. Incorrect e. the rib muscles and diaphragm contract, increasing the lung volume. Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Generation of proton gradients across membranes occurs during Choose one answer. a. photosynthesis. Incorrect b. respiration. Incorrect c. photorespiration. Incorrect d. neither photosynthesis nor respiration. Incorrect e. both photosynthesis and respiration. Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? Choose one answer. a. inability of chromosomes to meet at the metaphase plate Incorrect b. lack of appropriate cell death Correct c. metastasis Incorrect d. changes in the order of cell cycle stages Incorrect e. inability to form spindles Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is composed of chemical building blocks called nucleotides. Incorrect

b. Genes are composed of deoxyribonucleic acid. Incorrect c. DNA is an enzyme that puts together amino acids to make a protein. Correct d. DNA is a code for the sequence of amino acids in a protein. Incorrect e. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The plant's height is 25 centimeters (cm). Incorrect b. The contents of the stomach are mixed every 20 seconds. Incorrect c. The six pairs of robins hatched an average of three chicks. Incorrect d. The temperature decreased from 20C to 15C. Incorrect e. The fish swam in a zig-zag motion. Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following describes peristalsis in the digestive system? Choose one answer. a. a common cause of loss of appetite, fatigue, and dehydration Incorrect b. smooth muscle contractions that move food through the alimentary canal Correct c. voluntary control of the rectal sphincters regulating defecation Incorrect d. the transport of nutrients to the liver through the hepatic portal vessel Incorrect e. a process of fat emulsification in the small intestine Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will Choose one answer. a. rapidly increase. Incorrect b. rapidly decline. Incorrect c. gradually increase. Incorrect d. remain unchanged. Incorrect e. gradually decline. Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 What is a chromatid? Choose one answer. a. another name for the chromosomes found in genetics Incorrect b. a special region that holds two centromeres together Incorrect c. a replicate chromosome Correct d. a chromosome in G1 of the cell cycle Incorrect e. a chromosome found outside the nucleus Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, whereas a different process that could have potentially contributed to the cluster's presence on more than one chromosome was __________. I. binary fission II. translation III. gene duplication IV. non-disjunction V. transcription Choose one answer. a. I, II Incorrect b. III, IV Correct c. III, V Incorrect d. II, III Incorrect e. II, V Incorrect Incorrect Marks for this submission: 0/1.

Question 19 Marks: 1 Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? Choose one answer. a. a cell's ability to distinguish one type of neighboring cell from another Correct b. maintaining the integrity of a fluid mosaic membrane Incorrect c. facilitated diffusion of molecules down their concentration gradients Incorrect d. maintaining membrane fluidity at low temperatures Incorrect e. active transport of molecules against their concentration gradients Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Most genes have many more than two alleles. However, which of the following is also true? Choose one answer. a. At least one allele for a gene always produces a dominant phenotype. Incorrect b. Most of the alleles will never be found in a live-born organism. Incorrect c. There may still be only two phenotypes for the trait. Correct d. All of the alleles but one will produce harmful effects if homozygous. Incorrect e. More than two alleles in a genotype is lethal. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. a. the starch solution has less free energy than the sugar solution. Incorrect b. starch cannot be hydrolyzed in the presence of so much water. Incorrect c. starch hydrolysis is nonspontaneous. Incorrect d. the activation energy barrier for this reaction cannot be surmounted. Correct e. the hydrolysis of starch to sugar is endergonic. Incorrect Correct Marks for this submission: 1/1. Question 22 Marks: 1 Which of these statements is false? Choose one answer. a. In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). Incorrect b. At sexual maturity, ovaries and testes produce diploid gametes by meiosis. Correct c. In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. Incorrect d. Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. Incorrect e. Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. interaction with the environment Incorrect b. evolution Incorrect c. reductionism Correct d. structure and function Incorrect e. emergent properties Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight when denied air. Curiously, the consumption of sugar increases as air is removed from the organism's environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the organism does fine. Which of the following best describes the organism? Choose one answer. a. It is an anaerobic organism. Incorrect b. It is a normal eukaryotic organism. Incorrect c. The organism obviously lacks the citric acid cycle and electron transport chain. Incorrect d. It must use a molecule other than oxygen to accept electrons from the electron transport chain. Incorrect e. It is a facultative anaerobe. Correct Incorrect Marks for this submission: 0/1. Question 25

Marks: 1 New combinations of linked genes are due to which of the following? Choose one answer. a. Crossing over Correct b. Nondisjunction Incorrect c. Mixing of sperm and egg Incorrect d. Deletions Incorrect e. Independent assortment Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? Choose one answer. a. ADP, Pi, and NADP+ Incorrect b. CO2 and glucose Incorrect c. electrons and H+ Incorrect d. ATP and NADPH Correct e. H2O and O2 Incorrect Correct Marks for this submission: 1/1. Question 27 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 12 Incorrect b. 2 Incorrect c. 1 Incorrect d. 38 Incorrect e. 6 Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. Bowman's capsule Incorrect b. glomerulus Incorrect c. loop of Henle Correct d. collecting duct Incorrect e. proximal convoluted tubule Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 What is the source of the extra chromosome 21 in an individual with Down syndrome? Choose one answer. a. Nondisjunction or translocation in either parent Correct b. Duplication of the chromosome Incorrect c. Nondisjunction in the father only Incorrect d. It is impossible to detect with current technology Incorrect e. Nondisjunction in the mother only Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, -S Correct b. +G, +H, +S Incorrect c. -G, +H, +S Incorrect d. +G, -H, -S Incorrect e. -G, -H, -S Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Where do the enzymatic reactions of the Calvin cycle take place? Choose one answer.

a. thylakoid space Incorrect b. thylakoid membranes Incorrect c. outer membrane of the chloroplast Incorrect d. electron transport chain Incorrect e. stroma of the chloroplast Correct Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. a boy mowing grass Incorrect b. water rushing over Niagara Falls Incorrect c. an insect foraging for food Incorrect d. a firefly using light flashes to attract a mate Incorrect e. a food molecule made up of energy-rich macromolecules Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following steps has not yet been accomplished by scientists studying the origin of life? Choose one answer. a. abiotic synthesis of organic molecules Incorrect b. formation of protobionts that use DNA to direct the polymerization of amino acids Correct c. abiotic synthesis of polypeptides Incorrect d. formation of molecular aggregates with selectively permeable membranes Incorrect e. synthesis of small RNA polymers by ribozymes Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which life cycle stage is found in plants but not animals? Choose one answer. a. Gamete Incorrect b. Zygote Incorrect c. Multicellular haploid Correct d. Unicellular diploid Incorrect e. Multicellular diploid Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Fungi Correct c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Plantae Incorrect e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which of the following descriptions best fits the class of molecules known as nucleotides? Choose one answer. a. a pentose sugar and a purine or pyrimidine Incorrect b. a nitrogenous base, a phosphate group, and a pentose sugar Correct c. a phosphate group and an adenine or uracil Incorrect d. a nitrogenous base and a phosphate group Incorrect e. a nitrogenous base and a pentose sugar Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 ? HCO3- + H+ If the pH of the blood drops, one would expect

Choose one answer. a. the concentration of bicarbonate ion (HCO3-) to increase. Incorrect b. the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3. Incorrect c. the concentration of hydroxide ion (OH-) to increase. Incorrect d. the HCO3- to act as a base and remove excess H+ with the formation of H2CO3. Correct e. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. Incorrect Correct Marks for this submission: 1/1. Question 38 Marks: 1 Familial hypercholesterolemia is characterized by which of the following? Choose one answer. a. poor attachment of the cholesterol to the extracellular matrix of cells Incorrect b. a general lack of glycolipids in the blood cell membranes Incorrect c. a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes Incorrect d. inhibition of the cholesterol active transport system in red blood cells Incorrect e. defective LDL receptors on the cell membranes Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. oxygen Incorrect b. NADH Correct c. pyruvate Incorrect d. lactate Incorrect e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 What is unique about transport epithelial cells in the ascending loop of Henle in humans? Choose one answer. a. They are the largest epithelial cells in the body. Incorrect b. They are not affected by high levels of nitrogenous wastes. Incorrect c. They are not in contact with interstitial fluid. Incorrect d. Their membranes are impermeable to water. Correct e. 50% of their cell mass is comprised of smooth endoplasmic reticulum. Incorrect Correct Marks for this submission: 1/1. Question 41 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. ureter Incorrect b. urethra Incorrect c. podocytes Incorrect d. juxtamedullary nephrons Correct e. Bowman's capsule Incorrect Correct Marks for this submission: 1/1. Question 42 Marks: 1 Cystic fibrosis (CF) is a Mendelian disorder in the human population that is inherited as a recessive. Two normal parents have two children with CF. The probability of their next child being normal for this characteristic is which of the following? Choose one answer. a. 0 Incorrect b. 1/2 Incorrect c. 1/4 Correct d. 1/8 Incorrect e. 3/4 Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer.

a. act as oxidizing agents Incorrect b. both oxidize and reduce during electron transport Correct c. donate electrons Incorrect d. transport protons within the mitochondria and chloroplasts Incorrect e. act as reducing agents Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which event is nearest in time to the end of the period known as snowball Earth? Choose one answer. a. evolution of true multicellularity Incorrect b. oxygenation of Earth's seas and atmosphere Incorrect c. Permian extinction Incorrect d. evolution of mitochondria Incorrect e. Cambrian explosion Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that to keep the frogs in a smoke-filled environment for defined periods would result in lung cancer in the animals. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly) they knew that a more likely outcome would be which of the following? Choose one answer. a. the amphibian equivalent of hypertension Incorrect b. diminished absorption of oxygen Incorrect c. tracheal tube abnormalities Incorrect d. gill abnormalities in the next generation of tadpoles Incorrect e. skin cancer Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following statements correctly describes geometric isomers? Choose one answer. a. They have variations in arrangement around a double bond. Correct b. They have the same chemical properties. Incorrect c. Their atoms and bonds are arranged in different sequences. Incorrect d. They have different molecular formulas. Incorrect e. They have an asymmetric carbon that makes them mirror images. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 A woman has six sons. The chance that her next child will be a daughter is Choose one answer. a. 0. Incorrect b. 5/6. Incorrect c. 1/6. Incorrect d. 1. Incorrect e. 1/2. Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct b. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect c. transfers large molecules as easily as small ones. Incorrect d. is very selective as to which subprotein sized molecules are transferred. Incorrect e. results from active transport. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Emphysema is a disease, frequently caused by smoking, that results in loss of the elastic elements of lung tissue. The effect will be more like which of the following? Choose one answer.

a. an increase in airway resistance Correct b. pulmonary edema in which the alveoli amass fluid Incorrect c. a decrease in airway resistance Incorrect d. bronchiolar constriction as in asthma Incorrect e. cystic fibrosis in which mucus builds up in the lungs Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Thyroid hormone is increased. Incorrect b. Both insulin and glucagon decrease. Incorrect c. Both insulin and glucagon increase. Incorrect d. Blood glucagon increases. Correct e. Blood insulin increases. Incorrect Correct Marks for this submission: 1/1. Question 51 Marks: 1 Which of the following statements about genes is incorrect? Choose one answer. a. Genes correspond to segments of DNA. Incorrect b. Many genes contain the information needed for cells to synthesize enzymes and other proteins. Incorrect c. One gene only is used in a specific cell type. Correct d. During fertilization, both the sperm and the ovum contribute genes to the resulting fertilized egg. Incorrect e. Genetic differences can result from changes in the DNA called mutations. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped to make possible the evolution of the tetrapod limb. This type of change is illustrative of Choose one answer. a. paedomorphosis. Incorrect b. the influence of environment on development. Incorrect c. gene duplication. Incorrect d. heterochrony. Incorrect e. a change in a developmental gene or in its regulation that altered the spatial organization of body parts. Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following produces and modifies polysaccharides that will be secreted? Choose one answer. a. Golgi apparatus Correct b. vacuole Incorrect c. lysosome Incorrect d. mitochondrion Incorrect e. peroxisome Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is Choose one answer. a. the percentage of carbohydrates in the component. Incorrect b. the relative solubility of the component. Incorrect c. the size and weight of the component. Correct d. the number of enzymes in the fraction. Incorrect e. the presence or absence of lipids in the component. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 The ATP made during glycolysis is generated by Choose one answer. a. photophosphorylation. Incorrect b. electron transport. Incorrect

c. substrate-level phosphorylation. Correct d. chemiosmosis. Incorrect e. oxidation of NADH to NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 How many grams of acetic acid (C2H4O2) would you use to make 10 L of a 0.1 M aqueous solution of acetic acid? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) Choose one answer. a. 6.0 g Incorrect b. 10.0 g Incorrect c. 0.1 g Incorrect d. 0.6 g Incorrect e. 60.0 g Correct Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 A patient has a blood pressure of 120/75, a pulse rate of 40 beats/min, a stroke volume of 70 mL/beat, and a respiratory rate of 25 breaths/min. This person's cardiac output per minute will be Choose one answer. a. 2,800 mL. Correct b. 500 mL. Incorrect c. 1,750 mL. Incorrect d. 4,800 mL. Incorrect e. 1,000 mL. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which structure is not part of the endomembrane system? Choose one answer. a. chloroplast Correct b. plasma membrane Incorrect c. Golgi apparatus Incorrect d. nuclear envelope Incorrect e. ER Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Where are the molecules of the electron transport chain found in plant cells? Choose one answer. a. inner membrane of mitochondria Incorrect b. cytoplasm Incorrect c. thylakoid membranes of chloroplasts Correct d. matrix of mitochondria Incorrect e. stroma of chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. a sufficient colony of H. pylori Incorrect b. high level of secretion from parietal cells Incorrect c. mucus secretion and active mitosis of epithelial cells Correct d. secretions entering the stomach from the pancreas Incorrect e. high level of secretion by chief cells Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 5 Started on Saturday, January 17, 2009, 08:32 AM Completed on Saturday, January 17, 2009, 08:33 AM Time taken 1 min 39 secs

Raw score 14/60 (23%) Grade out of a maximum of Question 1 Marks: 1 Compared to the seawater around them, most marine invertebrates are Choose one answer. a. isoosmotic. Correct b. hyperosmotic. Incorrect c. hypoosmotic. Incorrect d. hyperosmotic and isoosmotic. Incorrect e. hypoosmotic and isoosmotic. Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 Evolution is biology's core theme that ties together all the other themes. This is because evolution explains Choose one answer. a. why distantly related organisms sometimes resemble each other. Incorrect b. how organisms become adapted to their environment through the differential reproductive success of varying individuals. Incorrect c. the unity and diversity of life. Incorrect d. explains why some organisms have traits in common. Incorrect e. all of the above Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. can be made by the animal's body from other substances. Correct b. is not used by the animal in biosynthesis. Incorrect c. is less important than an essential amino acid. Incorrect d. must be ingested in the diet. Incorrect e. is not found in many proteins. Incorrect Correct Marks for this submission: 1/1. Question 4 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) is greater than item (B). Incorrect b. Item (A) may stand in more than one of the above relations to item (B). Incorrect c. Item (A) is less than item (B). Incorrect d. Item (A) is exactly or very approximately equal to item (B). Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 The blood level of which gas is most important in controlling human respiration rate? Choose one answer. a. carbon dioxide Correct b. nitric acid Incorrect c. carbon monoxide Incorrect d. oxygen Incorrect e. nitrogen Incorrect Correct Marks for this submission: 1/1. Question 6 Marks: 1 Which statement about natural selection is most correct? Choose one answer. a. Adaptations beneficial at one time should generally be beneficial during all other times as well. Incorrect b. Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well. Incorrect c. Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes. Incorrect d. Natural selection is the sole means by which populations can evolve. Incorrect e. Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals. Correct Incorrect Marks for this submission: 0/1.

Question 7 Marks: 1 Which of the following normally occurs whether or not oxygen (O2) is present? Choose one answer. a. citric acid cycle Incorrect b. oxidative phosphorylation (chemiosmosis) Incorrect c. fermentation Incorrect d. oxidation of pyruvate to acetyl CoA Incorrect e. glycolysis Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The existence of the phenomenon of exaptation is most closely associated with which of the following reasons that natural selection cannot fashion perfect organisms? Choose one answer. a. Natural selection and sexual selection can work at cross-purposes to each other. Incorrect b. Adaptations are often compromises. Incorrect c. Chance events affect the evolutionary history of populations in environments that can change unpredictably. Incorrect d. Evolution is limited by historical constraints. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? Choose one answer. a. 104M Incorrect b. 4% Incorrect c. 10-10M Incorrect d. 4.0 M Incorrect e. 10-4M Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a Choose one answer. a. lower osmotic pressure. Incorrect b. higher PO2. Correct c. higher PCO2. Incorrect d. lower pH. Incorrect e. greater bicarbonate concentration. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. kidneys of vertebrates Correct b. metanephridia of earthworms Incorrect c. Malpighian tubules of insects Incorrect d. protonephridia of rotifers Incorrect e. flame-bulb system of flatworms Incorrect Correct Marks for this submission: 1/1. Question 12 Marks: 1 Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species? 1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy Choose one answer. a. 2 and 4 Correct b. 1 and 3 Incorrect c. 2 and 3 Incorrect d. 1 and 4 Incorrect Correct Marks for this submission: 1/1. Question 13

Marks: 1 What is the hydroxide ion concentration of the lake described in question 7? Choose one answer. a. 10 M Incorrect b. 10-4M Incorrect c. 10-14 M Incorrect d. 10-10M Correct e. 10-7M Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect b. DNA is composed of chemical building blocks called nucleotides. Incorrect c. DNA is an enzyme that puts together amino acids to make a protein. Correct d. Genes are composed of deoxyribonucleic acid. Incorrect e. DNA is a code for the sequence of amino acids in a protein. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila in which of these ways? Choose one answer. a. The entire Drosophila genome has approximately 400 map units. Incorrect b. There are four major functional classes of genes in Drosophila. Incorrect c. Drosophila genes cluster into four distinct groups of linked genes. Correct d. The overall number of genes in Drosophila is a multiple of four. Incorrect e. Drosophila genes have, on average, four different alleles. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur? Choose one answer. a. Cells would carry on the Calvin cycle at a much slower rate. Incorrect b. More sugars would be produced. Incorrect c. There would be more light-induced damage to the cells. Incorrect d. Cells would carry on more photosynthesis. Incorrect e. Less ATP would be generated. Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a[[no]] Choose one answer. a. noncompetitive inhibitor of the enzyme. Incorrect b. competitive inhibitor of the enzyme. Incorrect c. allosteric activator of the enzyme. Incorrect d. cofactor necessary for enzyme activity. Correct e. coenzyme derived from a vitamin. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following metabolic processes can occur without a net influx of energy from some other process? Choose one answer. a. C6H12O6 + 6 O2 ? 6 CO2 + 6H2O Correct b. glucose + fructose ? sucrose Incorrect c. amino acids ? protein Incorrect d. 6 CO2 + 6 H2O ? C6H12O6 + 6 O2 Incorrect e. ADP + Pi ? ATP + H2O Incorrect Correct Marks for this submission: 1/1. Question 19 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected?

Choose one answer. a. A greater-than-normal volume of isoosmotic urine would be produced. Correct b. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect c. A less-than-normal volume of isoosmotic urine would be produced. Incorrect d. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect e. No urine would be produced. Incorrect Correct Marks for this submission: 1/1. Question 20 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. active transport Incorrect b. selective reabsorption Correct c. filtration Incorrect d. secretion Incorrect e. ultrafiltration Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that Choose one answer. a. the nuclear envelope is physically continuous with the endoplasmic reticulum. Incorrect b. small vesicles from the Golgi fuse with the nuclear envelope. Incorrect c. nuclear pore complexes contain proteins. Incorrect d. at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. Correct e. the nuclear envelope is not part of the endomembrane system. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is Choose one answer. a. PGAL. Incorrect b. RuBP. Incorrect c. glucose. Incorrect d. PGA. Incorrect e. O2. Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They can have very long carbon skeletons. Incorrect b. They are easily reduced. Incorrect c. They have no nitrogen in their makeup. Incorrect d. They have a lot of electrons associated with hydrogen. Correct e. They have a lot of oxygen atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. NADPH ? electron transport chain ? O2 Incorrect b. H2O ? NADPH ? Calvin cycle Correct c. NADPH ? chlorophyll ? Calvin cycle Incorrect d. NADPH ? O2 ? CO2 Incorrect e. H2O ? photosystem I ? photosystem II Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? Choose one answer. a. The number of phosphates is three instead of two. Incorrect b. The nitrogen-containing base is different. Incorrect

c. The number of phosphates is three instead of one. Incorrect d. The sugar molecule is different. Incorrect e. There is no difference. Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon increase. Incorrect b. Both insulin and glucagon decrease. Incorrect c. Thyroid hormone is increased. Incorrect d. Blood glucagon increases. Correct e. Blood insulin increases. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 The cyclin component of MPF is destroyed toward the end of this phase: Choose one answer. a. G0 Incorrect b. G1 Incorrect c. S Incorrect d. G2 Incorrect e. M Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. blood proteins Incorrect b. fat stored in the liver Incorrect c. muscle proteins Incorrect d. fat stored in adipose tissue Incorrect e. muscle and liver glycogen Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Eukarya, kingdom Fungi Correct b. domain Bacteria, kingdom Prokaryota Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Archaea, kingdom Bacteria Incorrect e. domain Eukarya, kingdom Plantae Incorrect Correct Marks for this submission: 1/1. Question 30 Marks: 1 When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype? Choose one answer. a. 50% Correct b. 100% Incorrect c. 75% Incorrect d. 0% Incorrect e. 25% Incorrect Correct Marks for this submission: 1/1. Question 31 Marks: 1 Genomic imprinting is generally due to the addition of methyl (-CH3) groups to C nucleotides in order to silence a given gene. If this depends on the sex of the parent who transmits the gene, which of the following must be true? Choose one answer. a. The imprints are transmitted only to gamete-producing cells. Incorrect b. Genes required for early development stages must not be imprinted. Incorrect c. Methylation must be reversible in ovarian and testicular cells. Correct

d. Methylation of this kind must occur more in males than in females. Incorrect e. Methylation of C is permanent in a gene. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes? Choose one answer. a. a cell that is digesting food particles Incorrect b. a cell that is enlarging its vacuole Incorrect c. a cell that is producing cytoplasmic enzymes Correct d. a cell that is constructing its cell wall or extracellular matrix Incorrect e. a cell that is secreting proteins Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. a. proteins and nucleic acids. Correct b. starch and cellulose. Incorrect c. fatty acids and glycerol. Incorrect d. triglycerides and steroids. Incorrect e. phospholipids and glycolipids. Incorrect Correct Marks for this submission: 1/1. Question 34 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. heat and fluorescence Incorrect b. ADP and NADP Incorrect c. ATP and P700 Incorrect d. P700 and P680 Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Why is it important that an experiment include a control group? Choose one answer. a. Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor. Correct b. The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results. Incorrect c. A control group assures that an experiment will be repeatable. Incorrect d. The control group provides a reserve of experimental subjects. Incorrect e. A control group is required for the development of an "if, then" statement. Incorrect Correct Marks for this submission: 1/1. Question 36 Marks: 1 What is the mechanism for the production of genetic recombinants? Choose one answer. a. Methylation of cytosine Incorrect b. Deletions and duplications during meiosis Incorrect c. Crossing over and independent assortment Correct d. X inactivation Incorrect e. Nondisjunction Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. NAD+. Incorrect b. pyruvate. Incorrect c. water. Incorrect d. oxygen. Correct e. ADP. Incorrect

Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Why isn't the mitochondrion classified as part of the endomembrane system? Choose one answer. a. It is not attached to the outer nuclear envelope. Incorrect b. It only has two membrane layers. Incorrect c. Its structure is not derived from the ER. Correct d. It has too many vesicles. Incorrect e. It is not involved in protein synthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 What is the reason that linked genes are inherited together? Choose one answer. a. Alleles are paired together during meiosis. Incorrect b. They are located close together on the same chromosome. Correct c. Chromosomes are unbreakable. Incorrect d. The number of genes in a cell is greater than the number of chromosomes. Incorrect e. Genes align that way during metaphase I of meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. a. rabbits, horses, and herbivorous bears Correct b. tapeworms and other intestinal parasites Incorrect c. humans and other primates Incorrect d. carnivorous animals Incorrect e. tubeworms that digest via symbionts Incorrect Correct Marks for this submission: 1/1. Question 41 Marks: 1 The mathematical expression for the change in free energy of a system is G =H-TS. Which of the following is (are) correct? Choose one answer. a. H is the change in entropy, the energy available to do work. Incorrect b. G is the change in free energy. Correct c. S is the change in enthalpy, a measure of randomness. Incorrect d. T is the temperature in degrees Celsius. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants Choose one answer. a. the spindles contain microfibrils in addition to microtubules, whereas animal spindles do not contain microfibrils. Incorrect b. sister chromatids are identical, but they differ from one another in animals. Incorrect c. chromosomes become attached to the spindle at prophase, whereas in animals chromosomes do not become attached until anaphase. Incorrect d. a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. Correct e. spindle poles contain centrioles, whereas spindle poles in animals do not. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 2 Incorrect b. 12 Incorrect c. 6 Correct d. 1 Incorrect e. 38 Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1

Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect b. a system to circulate gases, nutrients, and wastes to and from cells Correct c. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect d. a system of individualized exchange tubules for each cell group Incorrect e. direct exchange of nutrients with the surrounding medium Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect b. protein function at one site affected by binding at another of its active sites Incorrect c. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect d. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect e. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. hemoglobin. Correct b. plasma proteins. Incorrect c. plasma buffers. Incorrect d. carbonic acid. Incorrect e. carbon dioxide. Incorrect Correct Marks for this submission: 1/1. Question 47 Marks: 1 The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? Choose one answer. a. spindle attachment to kinetochores Incorrect b. spindle formation Incorrect c. cleavage furrow formation Correct d. DNA synthesis Incorrect e. cell elongation during anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Tidal volume in respiration is analogous to what measurement in cardiac physiology? Choose one answer. a. diastolic pressure Incorrect b. heart rate Incorrect c. stroke volume Correct d. systolic pressure Incorrect e. cardiac output Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 You have in your possession a microscope slide with meiotic cells on it and a light microscope. What would you look for if you wanted to identify metaphase I cells on the slide? Choose one answer. a. A visible nuclear envelope Incorrect b. Tetrads lined up at the center of the cell Correct c. A cleavage furrow Incorrect d. Separated sister chromatids at each pole of the cell Incorrect e. A synaptonemal complex Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that Choose one answer. a. humans and chimpanzees share a relatively recent common ancestor. Correct b. humans evolved from chimpanzees. Incorrect c. chimpanzees evolved from humans. Incorrect d. convergent evolution led to the DNA similarities. Incorrect e. humans and chimpanzees are not closely related. Incorrect Correct Marks for this submission: 1/1. Question 51 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. oxygen and carbon dioxide Incorrect b. electrons and photons Incorrect c. ATP and NADPH Correct d. water and carbon Incorrect e. carbon dioxide and RuBP Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not Choose one answer. a. possess a selectively permeable membrane boundary. Incorrect b. perform osmosis. Incorrect c. grow in size. Incorrect d. absorb compounds from the external environment. Incorrect e. perform controlled, precise reproduction. Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? Choose one answer. a. The cytochromes phosphorylate ADP to form ATP. Incorrect b. ATP synthase pumps protons by active transport. Incorrect c. NAD+ is oxidized. I