Biology 11, Fall 2002, Exam 1 Key

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1 Biology 11, Fall 2002, Exam 1 Key Name: Class Time: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1. The proper order of objects, from simple to complex, is a. atom, molecule, cell, tissue, organ, organism, population, community. b. cell, molecule, atom, tissue, organ, organism, population, community. c. molecule, cell, organ, atom, tissue, organism, population, community. d. atom, molecule, cell, tissue, organ, population, organism, community. e. atom, molecule, tissue, organ, cell, population, organism, community. 2. After observing that fish live in clean water but not in polluted water, you make the statement, polluted water kills fish. Your statement is an example of a. a controlled experiment. b. a field experiment. c. a laboratory experiment. d. a hypothesis. e. comparative analysis. 3. A 0.1 M solution of HCl has a ph of a b c d e. None of the above 4. An element has a mass weight of The reason the number includes 0.3 is because a. of the weight of electrons. b. of the average of naturally occurring isotopes. c. the neutrons do not have a single unit weight. d. all of the above. e. none of the above. 5. In a hydrogen molecule, the two atoms are held together by a. hydrogen bonds. b. a shared pair of electrons. c. Van der Waal forces. d. ionic attractions. e. neutron gravity. 6. Ionic bonds are a. attractions between oppositely charged ions. b. the result of electron sharing. c. the strongest of the chemical bonds. d. caused by partial electrical charges. e. all of the above. 7. What is the difference between an acid and a base? a. An acid undergoes a reversible reaction, while a base does not. b. An acid releases OH- ions in solution, while a base accepts OH- ions. c. An acid releases H+ ions in solution, while a base releases OH- ions. d. An acid releases OH- ions in solution, while a base releases H+ ions. e. An acid releases H+ ions in solution, while a base accepts H+ ions.

2 8. A cell is composed of compounds that include proteins, nucleic acids, lipids, and carbohydrates. A cell is capable of reproduction, but when the compounds that make up a cell are isolated, none of them can reproduce. Thus, cell reproduction is an example of a. growth. b. a molecule. c. an emergent property. d. adaptation. e. metabolism. 9. Which is not a consequence of hydrogen bonding? a. The attraction between water molecules b. The shape of proteins and DNA c. The high solubility of a sugar in water d. Capillary action e. All of the above 10. Two carbon atoms held together in a double covalent bond share electron(s). a. one b. two c. four d. six e. eight 11. The four elements most common in organisms are a. Calcium, iron, hydrogen, and oxygen. b. Water, carbon, hydrogen, and oxygen. c. Carbon, oxygen, hydrogen, and nitrogen. d. Nitrogen, carbon, iron, and hydrogen. e. Phosphorus, water, carbon, and oxygen. 12. Of the following atomic configurations, the one that has an atomic mass of 14 is the atom with a. 14 neutrons. b. 14 electrons. c. 7 neutrons and 7 electrons. d. 7 protons and 7 electrons. e. 6 protons and 8 neutrons. 13. The number of protons in an atom equals the number of a. neutrons. b. electrons. c. electrons plus neutrons. d. neutrons minus electrons. e. quarks. 14. The bonds that form between the units of polymeric macromolecules are a. hydrogen. b. peptide. c. disulfide. d. covalent. e. ionic. 15. You have isolated an unidentified liquid from a sample of beans. You add the liquid to a beaker of water and shake vigorously. After a few minutes, the water and the other liquid separate into two layers. To which class of large biological molecules does the unknown liquid most likely belong? a. Carbohydrates b. Lipids c. Proteins d. Enzymes e. Nucleic acids

3 16. Which of the following monomer/polymer pairs is NOT correct? a. monosaccharide/polysaccharide b. amino acid/protein c. tryglyceride/lipid d. nucleotide/dna e. nucleotide/rna 17. Two important polysaccharides made up of glucose monomers are a. guanine and cytosine. b. RNA and DNA. c. sucrose and lactose. d. cellulose and starch. e. testosterone and cortisone. 18. In animals, glucose is stored in the compound a. cellulose. b. amylose. c. glycogen. d. fructose. e. cellobiose. 19. What is the nucleotide sequence of the complementary strand of this DNA molecule: AATGCGA? a. CCGTTAT b. AATGCGA c. GGCATAG d. TTACGCT e. AGCGTAA 20. What type of amino acid side chains would you expect to find on the surface of a protein embedded in a cell membrane? a. Cysteine (CH 2 SH) b. Hydrophobic c. Hydrophilic d. Charged e. Polar, but not charged 21. When a protein becomes nonfunctional as a result of a change in its environment, it is a. permanent b. reversible c. denatured d. egg white e. environmentalized 22. Enzymes are a. DNA b. Lipids c. Carbohydrates d. Protein e. Amino acids 23. How many grams of the molecule, C 2 H 4 O 2, (mol wt: C =12, H =1, O =16) should one add to a liter of water to make a 0.4 M solution? a. 12 b. 24 c. 8 d. 60 e. 32

4 24. Fatty acids are molecules that a. contain fats b. are carboxylic acids c. are carbohydrates d. contain glycerol e. are always saturated 25. Components of chloroplasts include a. grana b. thylakoids c. cristae d. a and b e. a,b, and c 26. What is the major distinction between prokaryotic and eukaryotic cells? a. prokaryotic cells have not prospered, while eukaryotic cells are evolutionary successes. b. a prokaryotic cell does not have DNA, and a eukaryotic cell does. c. prokaryotic cells are smaller than eukaryotic cells. d. a prokaryotic cell does not have a nucleus, and a eukaryotic cell does. e. prokaryotic cells cannot obtain energy from their environment. 27. Using a light microscope it is possible to view cytoplasm streaming around the central vacuole in cells of the green alga Nitella. Why would you use a light microscope instead of an electron microscope to study this process? a. Electron microscopes have less resolving power than light microscopes. b. Structures inside the cell cannot be seen with the electron microscope. c. Whole cells cannot be viewed with the electron microscope d. The electron microscope cannot be used to observe living cells e. The central vacuole is too small to be seen with a scanning electron microscope. 28. Which of the following is a general function of all cellular membranes? a. They regulate which materials can cross the membrane. b. They support the cell and determine its shape c. They produce energy for the cell d. They produce proteins for the cell e. They move the cell 29. What is the difference between free and attached ribosomes? a. Free ribosomes are in the cytoplasm, while attached ribosomes are anchored to the endoplasmic reticulum. b. Free ribosomes produce proteins in the cytosol, while attached ribosomes produce proteins that are inserted into the ER. c. Free ribosomes produce proteins that are exported from the cell, while attached ribosomes make proteins for mitochondria and chloroplasts. d. a and c e. a and b 30. Microtubules are made of a. actin and function in locomotion. b. tubulin and are found in cilia. c. tubulin and are found in microvilli. d. actin and function to change cell shape. e. polysaccharides and function in locomotion. 31. The overall shape of a cell is determined by its a. cell membrane b. cytoskeleton c. nucleus d. cytosol e. endoplasmic reticulum

5 32. The membranes of the endoplasmic reticulum are continuous with the membranes of the a. nucleus b. Golgi apparatus c. nucleolus d. plasma membrane e. mitochohdria 33. Substances move through biological membranes against concentration gradients via a. simple osmosis. b. active transport. c. reverse osmosis. d. a and b e. none of the above. 34. Houseplants adapted to indoor temperatures might die when accidentally left outdoors in cold because their a. DNA cannot function. b. membranes lack adequate fluidity. c. photosynthesis is impaired. d. chloroplasts malfunction. e. membranes need more cholesterol. 35. A protein that forms an ion channel through a membrane is most likely to be a. a peripheral protein. b. an integral protein. c. a phospholipid. d. an enzyme. e. antirely outside the phospholipid bilayer. 36. Structures that contain networks of keratin fibers and hold adjacent cells together are called a. extracellular matrices b. glycoproteins. c. gap junctions. d. desmosomes. e. phospholipid bilayers. 37. Which of the following does not affect the rate of diffusion of a substance? a. Temperature b. Concentraion gradient c. Electrical charge of the diffusing material d. Presence of other substances in the solution e. Molecular diameter of the diffusing material 38. Transporting substances across a membrane from an area of lower concentration to an area of higher concentration requires a. phospholipids. b. diffusion. c. gap junctions. d. facilitated diffusion. e. energy. 39. In the parietal cells of the stomach, the uptake of chloride ions is coupled to the transport of bicarbonate ions out of the cell. This type of transport system is called a. a uniport. b. a symport. c. an exchange channel. d. diffusion. e. an antiport.

6 40. When vesicles from the Gogi apparatus deliver their contents to the exterior of the cell, they add their membranes to the plasma membrane. Why doesn t the plasma membrane increase in size? a. some vesicles from the Golgi apparatus fuse with the lysosomes b. membrane vesicles carry proteins from the endoplasmic reticulum to the Golgi apparatus. c. membrane is continually being lost from the plasma membrane by endocytosis. d. new phospholipids are synthesized in the endoplasmic reticulum. e. the phospholipids become more tightly packed together in the membrane. 41. If you compare the proteins of the plasma membrane and the proteins of the inner mitochondrial membrane, which of the following will be true? a. Both membranes will have only peripheral proteins. b. Only the mitochondrial membrane will have integral proteins. c. Only the mitochondrial membrane will have peripheral proteins. d. All of the proteins from both membranes will be hydrophilic. e. The proteins from the two membranes will be different. Figure Glucose and fructose (figure 1) are a. geometric isomers. b. functional groups. c. hydrocarbons. d. enantiomers. e. structural isomers. 43. Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen? a. a steroid such as testosterone b. an alcohol such as ethanol c. a hydrocarbon such as benzene d. a compound of fats such as glycerol e. an amino acid such as glycine 44. A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should she add to the molecule? a. amino b. hydroxyl c. sulfhydryl d. carboxyl e. phosphate 45. Which two functional groups are always found in amino acids? a. carbonyl and carboxyl b. ketone and amine c. alcohol and aldehyde d. amine and sulfhydryl e. carboxyl and amine

7 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Refer to the following five terms to answer the next questions. Choose the most appropriate term for each phrase. Each term may be used once, more than once, or not at all. A. centriole B. lysosome C. nucleolus D. peroxisome E. ribosome 46. possesses a microtubular structure similar in form to a basal body A 47. assembles ribosomal precursors C Figure 2 Use the diagram of the U-tube setup) to answer the following question. The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is filled with a solution of 2 M sucrose and 1 M glucose. Side B is filled with 1 M sucrose and 2 M glucose. 48. After the system reaches equilibrium (figure 2), what changes are observed? a. The water level is higher in side A than in side B. b. The molarity of sucrose and glucose are equal on both sides. c. The molarity of glucose is higher in side A than in side B. d. The water level is unchanged. e. The molarity of sucrose is increased in side A. 49. Which of the following statements is CORRECT about diffusion? a. It occurs when molecules move from a region of lower concentration to one of higher concentration. b. It requires an expenditure of energy by the cell. c. It requires integral proteins in the cell membrane. d. It is very rapid over long distances. e. It is a passive process. 50. According to the fluid-mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids? a. They frequently flip-flop from one side of the membrane to the other. b. They have hydrophilic tails in the interior of the membrane. c. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. d. They are free to depart from the membrane and dissolve in the surrounding solution. e. They can move laterally along the plane of the membrane. Bonus Question (5 pts) 51. List three unique properties of water and explain what the mechanism(s) is(are) that underlies these properties. 1. High specific heat 2. High surface tension 3. high cohesion 4. solid is less dense than liquid 5. capillary action All caused by the hydrogen bonds between the water molecules.