GENERAL BIOLOGY 1 EXAM 1

GENERAL BIOLOGY 1 EXAM 1 BE SURE TO: • Bubble in your n# • Read all questions carefully 1. Which of the following is NOT a property of life? A. Living things have the ability to store and use information. B. Living things have the ability to create energy. C. Living things are composed of cells. D. Living things undergo evolutionary adaptation. E. Living things have the ability to replicate. 2. Which statement is not a component of the cell theory? A. All organisms are made of cells. B. All cells arose from RNA-based systems. C. All cells come from pre-existing cells. D. All of the above are components of the cell theory. 3. Which choice is an example of artificial selection? A. The long neck of a giraffe. B. Dog breeds with short legs. C. Ants trying to find their nest while walking on stilts. D. All of the above result from artificial selection. 4. Which choice best describes evolution? A. The characteristics of a species become more complex over time. B. The strongest individuals produce the most offspring. C. The characteristics of an individual change over the course of its life. D. The characteristics of a population change over time. 5. In an experiment, investigators try to control all of the variables except one—the one that tests the hypothesis. Which of the following reasons is the primary rationale for controlling variables in an experiment? A. To enable investigators to repeat the test. B. To create a control group. C. To eliminate alternative explanations for the results of an experiment. 6. Louis Pasteur’s experiments with different flasks disproved which hypothesis? A. All organisms are made of cells. B. Spontaneous generation. C. Evolution. D. All cells come from pre-existing cells. 7. You have isolated and purified a new species of single-celled organism from the arctic ocean and you want to place this new species in the appropriate branch of the tree of life. You sequence the ribosomal RNA genes from these cells and discover that for one particular region of the ribosomal gene the RNA sequence is AAUGAAGG. You have sequences from the same region of the ribosomal genes from each of these organisms: bacteria, eukaryote and archaea, which are listed below. bacteria AUAGAUGG eukaryote AAAGAAGG archaea AAUGGAGU Based on these sequence results, to which branch of the tree of life should you assign this new species? A. Archaea B. Bacteria C. Bacteria and archaea D. Eukaryote E. There is not enough information 8. Humans are eukaryotes. A. True B. False 9. Which of the following best describes a hypothesis? A. A hypothesis is like a blind guess. B. A hypothesis is a testable explanation for an observation. C. A hypothesis is proof of an idea. D. A hypothesis is a conclusion drawn from experiments. 10. One ml (milliliter) of an experimental drug diluted in a saline (salt) solution is injected into 20 pregnant mice to determine possible side effects. Which of the following is a suitable "control" for this experiment? A. 20 male mice injected with 1 ml of saline. B. 20 male mice injected with 1 ml of the drug. C. 20 pregnant mice injected with 1 ml of saline. D. 20 non-pregnant mice injected with 1 ml of the drug. 11. Sarah and Todd go to a new restaurant and do not like the food they are served. Their hypothesis is that if they go to the restaurant again, they will not like the food. If they continue to follow the scientific method, what should they do next? A. Never go near the restaurant again and tell all their friends to avoid it. B. Go back to the restaurant several times and order different items. C. Survey other customers to see if they like the food. D. Call the city health inspectors and suggest they inspect the restaurant. E. Get some friends to go to the restaurant and order what Sarah and Todd didn’t like. 12. A hydrogen bond results when which of the following conditions are met? A. Polar molecules interact through weak electrical attractions. B. The atoms involved lose their valence electrons. C. Bonds are formed between inert elements. D. Any covalent bond that includes a hydrogen atom. E. One partner donates an electron to the other. 13. Which of the following is NOT an example of potential energy? A. Water held behind a dam. B. Covalent bonds in a fat molecule. C. Heat. D. Gas pressure inside an unopened soft drink can. 14. Two atoms that have the same number of protons and electrons, but different numbers of neutrons are called . A. isotopes B. elements C. compounds D. inert 15. When two atoms share a pair of electrons, they are held together by a(n) . A. covalent bond B. ionic bond C. hydrogen bond D. electron bond 16. The chemical behavior of an atom is determined by . A. the configuration of electrons in its outer shell. B. how many protons it has in its nucleus. C. whether or not it has extra neutrons. D. None of the above. 17. Which statement best explains the physical basis for why oil (molecules containing only carbon and hydrogen) and water do not mix? A. Oils are negatively charged molecules that are repelled by the partial negative charges on water molecules. B. Oils are positively charged molecules that are repelled by the partial positive charges on water molecules. C. Oils are nonpolar molecules that cannot interact with water molecules via hydrogen bonding. D. Oil molecules interact via hydrogen bonding more strongly with other oil molecules than with water molecules. 18. Water molecules are polar because . A. the atoms that make up a water molecule are held together by hydrogen bonds. B. oxygen is more electronegative than hydrogen. C. electrons are shared equally by oxygen and hydrogen. D. most water exists at the north and south poles. 19. Why is carbon so important in biology? A. It is a common element on Earth. B. It has very little electronegativity, making it a good electron donor. C. It can form up to four covalent bonds to create a wide variety of carbon skeletons. D. It bonds to only a few other elements. 20. Which of the following is true of functional groups? A. They usually make organic molecules more hydrophilic. B. They can be added to organic molecules in a wide variety of combinations. C. They contribute to a molecule’s chemical properties. D. All of the above. 21. Which two functional groups are present on every amino acid? A. Phosphate group and hydroxyl group B. Carboxyl group and amino group C. Carboxyl group and hydroxyl group D. Phosphate group and amino group 22. Polymers are built from monomers through condensation reactions. A. True B. False Which does not belong in a group with the others? A. Peptide bond B. Hydrogen bond C. Glycosidic bond D. Phosphodiester bond 23. Which bond is a peptide bond? 24. What do alpha-helices and beta-sheets have in common? A. They are only found in enzymes. B. They are stabilized by hydrogen bonds on the peptide backbone. C. They are both shaped like a coil. D. They represent the overall shape of a complete protein. 25. Aquaporins are proteins that control the passage of water molecules across a cell membrane. The protein forms a pore, or opening, in the membrane. You isolate what you think are two different molecules of aquaporin, and determine that one of the proteins has a larger pore diameter than the second. Which of the following can you conclude? A. These two forms of aquaporin will have different sequences of amino acids. B. These two forms of aquaporin will have identical sequences of amino acids. C. You will have to sequence the proteins to compare their primary structure, because it should have no effect on pore diameter. D. These two forms of aquaporin have identical primary structure but differ in their tertiary structure. 26. The tertiary structure of a protein is stabilized by . A. hydrogen bonds B. ionic interactions C. disulfide bonds D. hydrophobic interactions E. All of the above 27. Which “equation” below most closely describes a condensation reaction? [M = monomer] A. M1-M2 - M1 + M2 + H2O B. M1 + M2 + H2O - M1-M2 C. M1-M2 + H2O - M1 + M2 D. M1 + M2 - M1-M2 + H2O 28. You disrupt all of the hydrogen bonds in a protein. What level of protein structure will be preserved? A. Primary B. Secondary C. Tertiary D. Quaternary 29. Which amino acid side chain is most likely to form hydrogen bonds with water or other polar molecules? .. . A B C D 30. Which cellular activity is not primarily carried out by proteins? A. Signaling B. Transport C. Information storage D. Movement E. Catalysis 31. All enzymes are proteins, but not all proteins are enzymes. A. True B. False 32. The proper base pairs in a DNA molecule are: A. Adenine-guanine and cytosine-thymine B. Adenine-cytosine and guanine-thymine C. Adenine-uracil and guanine-thymine D. Adenine-thymine and guanine-cytosine 33. The two strands of a DNA molecule are held together by _. A. hydrophobic interactions B. hydrogen bonds C. ionic interactions D. disulfide bonds E. All of the above. 34. The covalent backbone of nucleic acids is a repeating unit of . A. amino acids B. bases C. sugars D. sugars and phosphates 35. Why is it that RNA can catalyze reactions but DNA cannot? A. The primary structure of RNA is fundamentally different than the primary structure of DNA. B. The sugar of RNA is has a 2’ oxygen atom that the sugar of DNA does not have. C. The bases of RNA are more reactive than the bases of DNA. D. The phosphate groups of RNA are more reactive than the phosphate groups of DNA. 36. You have isolated nucleic acid from a cell. How can you tell if it is RNA or DNA? A. Determine its base composition. B. Determine whether or not it has phosphate groups. C. Determine if it has double-stranded regions. D. Determine its polarity. 37. Which choice is correct regarding the differences between starch and cellulose? A. Starch is a polymer of alpha-glucose; cellulose is a polymer of alpha-galactose. B. Cellulose functions to store energy; starch is a structural molecule. C. Starch is readily digested by most animals; cellulose is highly resistant to digestion. D. None of the above are correct. 38. Glucose is to as is to nucleic acid. A. galactose; polypeptide B. glycogen; nucleotide C. starch; amino acid D. protein; amino acid 39. Fats store more energy that carbohydrates because they have more high-energy carbon-carbon and carbon-hydrogen bonds, and carbohydrates have more lower-energy carbon-oxygen bonds. A. True B. False 40. Which of the following is NOT a function of carbohydrates? A. Energy storage B. Cellular recognition C. Cell structure D. All of the above are carbohydrate functions. 41. You construct a bilayer with equal amounts of saturated and unsaturated phospholipids. After determining the degree of permeability of this membrane to glucose (there was some permeability), you increase the proportion of unsaturated phospholipids in the bilayer. What will happen to the membrane’s permeability to glucose? A. Permeability to glucose will increase. B. Permeability to glucose will decrease. C. Permeability to glucose will stay the same. D. You can’t predict the outcome. You simply have to make the measurement. 42. Which of the following is NOT an example of a lipid? A. Cholesterol B. Peptidoglycan C. Triacylglycerol D. Phospholipid 43. Phospholipids spontaneously form a lipid bilayer in aqueous solution because they are . A. enzymes B. amphipathic C. hydrophobic D. pathetic 44. According to the fluid-mosaic model of membrane structure, proteins of the membrane are ___. A. spread in a continuous layer over the inner and outer surfaces of the membrane. B. confined to the hydrophobic core of the membrane. C. covalently attached to the phospholipids. D. embedded in a lipid bilayer. 45. If red blood cells are placed in distilled water: A. nothing will happen. B. so much water will enter the cells that they will burst. C. so much water will leave the cells that they will shrivel up. D. water will move equally in both directions across the membrane. 46. Which molecule would most rapidly pass through a plasma membrane by simple diffusion? A. Water B. Carbon dioxide C. Sodium ion D. Glucose 47. You are studying a system for transporting amino acids into cells and make the following observations: *The amino acids can move into or out of the cells, depending on the concentration gradient. *The amino acids are bound to a membrane protein during their passage through the membrane. *When ATP (energy) production by the cells is inhibited, transport of the amino acids is not affected. Based on the observations above, you conclude that the transport system is: A. active transport. B. osmosis. C. simple diffusion. D. facilitated diffusion. 48. A bacterium is expelled from a warm human intestine into the cold world outside. How will this bacterium have to adjust its lipid bilayer if it is to survive in this new environment? A. It will increase the length and saturation of hydrocarbon chains in its phospholipids. B. It will decrease the length and saturation of the hydrocarbon chains in its phospholipids. C. It will decrease the length and increase the saturation of the hydrocarbon chains in its phospholipids. D. It will increase the length and decrease the saturation of the hydrocarbon chains in its phospholipids. 49. Which of the following is true of carrier proteins? A. Transport of solute involves binding of the solute to the protein. B. Carrier proteins move solutes against their concentration gradient. C. Carrier proteins are primarily for passage of ions through a membrane. D. All of the above are true. 50. In cells, membrane proteins are responsible for the passage of substances that can't cross the membrane on their own. Channels and carrier proteins are involved in facilitated diffusion. Pumps are involved in active transport. In terms of their properties or functions, which statement most accurately describes how these three types of membrane proteins compare? A. Channels and carriers are integral membrane proteins; pumps are peripheral membrane proteins. B. Among the three types, only pumps can concentrate substances on one side of the membrane. C. Among the three types, only pumps are thought to undergo a shape change as part of their function. D. Pumps are selective; channels and carriers are not selective. 51. Extra credit! Tetrodotoxin is produced by Fugu pufferfish, an expensive Japanese delicacy. When properly prepared, a small amount of toxin is ingested, leading to feelings of euphoria; however up to 50 deaths occur in Japan every year through consumption of improperly prepared pufferfish. The structure of tetrodotoxin mimics a hydrated sodium ion. Death in these victims most likely occurs from: A. paralysis due to inhibition of nerve impulses. B. uncontrollable muscle spasms leading to cardiac arrest. C. depletion of sodium reserves leading to osmotic imbalance. D. nerve cell death from increased membrane permeability. DID YOU REMEMBER TO: • Bubble in your n#? • Read all questions carefully?