Chemistry Past Paper Exam 1 and 2 PDF

1. Which of the following is not one of the four most common elements in living organisms? a. Hydrogen b. Oxygen c. Nitrogen d. Sodium 2. In some areas, fluoride is added during the municipal water treatment process in order to help: a. reduce tooth decay....

1. Which of the following is not one of the four most common elements in living organisms? a. Hydrogen b. Oxygen c. Nitrogen d. Sodium 2. In some areas, fluoride is added during the municipal water treatment process in order to help: a. reduce tooth decay. b. prevent the growth of bacteria. c. prevent goiter. d. prevent delayed brain maturation. 3. Which trace element needed by humans is commonly added to table salt? a. chlorine b. iodine c. iron d. sodium 4. An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many neutrons does this atom have? a. 5 b. 6 c. 11 d. 16 5. A radioactive isotope of carbon __________ and contains __________. a. undergoes decay; more neutrons than protons b. is stable; more neutrons than protons c. undergoes decay; more protons than neutrons d. is stable; more protons than neutrons 6. Radioactive isotopes: a. are frequently added to foods as nutritional supplements. b. can be used in conjunction with PET scans to diagnose diseases. c. do not occur naturally. d. are never incorporated into organic compounds. 7. Nitrogen has an atomic number of 7. When full, the innermost electron shell of a nitrogen atom contains ________ electrons, and the outermost shell contains ________ electrons. a. 2, 5 b. 2, 7 c. 2, 8 d. 8, 8 8. Silicon is an element that is found directly underneath carbon in the periodic table and thus has similar properties to carbon, including electron orbitals. How many electrons are in the valence shell, which is the outer shell, of a silicon atom? a. 1 b. 2 c. 4 d. 6 9. What is the fundamental difference between covalent and ionic bonding? a. In covalent bonding, both partners end up with filled outer electron shells; in ionic bonding, one partner does and the other does not. b. In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other. c. Covalent bonds form between atoms of the same element; ionic bonds form between atoms of different elements. d. Covalent bonding involves only the outermost electron shell; ionic bonding also involves the next electron shell inside the outermost shell. 10. A nitrogen atom has seven electrons. How many single covalent bonds can nitrogen form? a. one b. two c. three d. four 11. The atomic number of lithium is 3, while the atomic number of chlorine is 17. When LiCl forms from these two atoms,: a. chlorine gives an electron to lithium. b. lithium and chlorine share electrons to form a bond. c. lithium donates its single outer electron to chlorine. d. a hydrogen bond forms between lithium and chlorine. 12. Medicines are often administered in pill form. In many cases, the active ingredient of the pill (the drug) is joined to another substance by ________. This forms a(n) ________, which is stable in the dry environment of a pill bottle but dissociates under the wet conditions of the digestive system to release the drug to the body. a. covalent bonds; hydrocarbon b. ionic bonds; hydrocarbon c. covalent bonds; salt d. ionic bonds; salt 13. The hydrogen atoms of a water molecule are bonded to the oxygen atom by ________ bonds, whereas neighboring water molecules are held together by ________ bonds. a. hydrogen; polar covalent b. ionic; covalent c. polar covalent; hydrogen d. polar covalent; ionic 14. Neighboring water molecules are held together by hydrogen bonding between positive __________ poles and negative __________ poles. a. hydrogen; hydrogen b. hydrogen; oxygen c. oxygen; oxygen d. oxygen; hydrogen 15. Which of the following statements about chemical reactions is NOT true? a. There are always the same number of atoms of each element on both sides of the arrow. b. In some chemical reactions, matter is created. c. Chemical reactions result in the rearrangement of atoms. d. Reactants yield products. 16. Which of the following is a balanced equation? a. H3PO4 + 2KOH → K3PO4 + 2H₂O b. H3PO4 + 2KOH → K3PO4 + 3H₂O c. H3PO4 + 3KOH → K3PO4 + 2H₂O d. H3PO4 + 3KOH → K3PO4 + 3H₂O 17. The tendency of water molecules to stick together is referred to as: a. adhesion. b. polarity. c. cohesion. d. transpiration. 18. How do adhesion and cohesion help water move through plants? a. Adhesion helps water molecules stick together, and cohesion helps water stick to the plant's surface. b. Adhesion makes water move faster through plants, and cohesion slows down the movement. c. Cohesion helps water molecules stick together, and adhesion helps water stick to the inside of plant tubes. d. Cohesion makes water evaporate, and adhesion helps water molecules form droplets. 19. How do hydrogen bonds in water help moderate temperature? a. They make water heat up and cool down quickly. b. They allow water to absorb and release heat slowly. c. They prevent water from freezing. d. They prevent water from boiling. 20. What is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water? a. the evaporative cooling of skin surfaces b. the milder temperatures of coastal regions compared to inland areas c. the ability of certain insects to walk on the surface of water d. the universality of water as a solvent 21. Which of the following statements about water is NOT true? a. Ice is denser than liquid water. b. If ice sank, the oceans would eventually freeze solid. c. Floating ice on a pond insulates the liquid water below, slowing its rate of freezing. d. Water naturally exists in all three physical states on Earth. 22. What makes water an excellent solvent for many substances? a. Water has a high density that helps it dissolve more substances. b. Water can dissolve a wide range of substances because it is a polar molecule with partial positive and negative charges. c. Water’s low boiling point allows it to dissolve substances more effectively. d. Water can dissolve only non-polar substances, making it a universal solvent. 23. You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which statement is true? a. The instant coffee and sugar are nonpolar and the water is polar, so they mix well. b. The instant coffee and sugar are polar and the water is nonpolar, so they mix well. c. The instant coffee and sugar are polar and the water is polar, so they mix well. d. The instant coffee and sugar are nonpolar and the water is nonpolar, so they mix well. 24. Which statement about pH is true? a. The pH scale is a measure of oxygen ion concentration. b. A single unit change on the pH scale is equivalent to a 1% change in hydrogen ion concentration. c. An increase in hydrogen ion concentration means a decrease in pH scale units. d. Basic pH levels are less than 7. 25. Some bases contribute __________ to an aqueous solution thus __________ the pH of the solution. a. H+; lowering b. H+; raising c. OH-; lowering d. OH-; raising e. Two of the above are correct. 26. In ocean acidification, dissolving CO2 gas ________ the pH of the ocean. a. lowers b. does not affect c. raises d. triples 27. How will ocean acidification affect coral reefs? a. Coral reefs will grow faster because there are more carbonate ions available. b. Coral reefs will grow slower because there are fewer carbonate ions available. c. Coral reefs will grow faster because there are more bicarbonate ions available. d. Coral reefs will grow slower because there are fewer bicarbonate ions available. 28. Propanol and isopropanol are isomers. This means that they have: a. different molecular formulas but the same chemical properties. b. the same molecular formula and the same chemical properties. c. the same molecular formula but different chemical properties. d. the same molecular formula but represent different states of the compound. 29. Which of the following statements about the functional groups of organic compounds is NOT true? a. All functional groups include a carbon atom. b. Functional groups may help make organic compounds hydrophilic. c. Many biological molecules have two or more functional groups. d. Functional groups participate in chemical reactions. 30. The __________ functional group consists of a hydroxyl group and a carbonyl group. a. amino b. carboxyl c. methyl d. phosphate 31. Below is the structure of octane, the major component of gasoline. The bonds in octane are __________ covalent because carbon and hydrogen atoms have quite __________ electronegativities. a. nonpolar; different b. nonpolar; similar c. polar; different d. polar; similar 32. In a hydrolysis reaction, __________. In this process, water is __________. a. a polymer breaks up to form monomers... inserted b. a polymer breaks up to form monomers... produced c. monomers are assembled to produce a polymer... inserted d. monomers are assembled to produce a polymer... produced 33. In a dehydration reaction, __________. In this process, water is __________. a. monomers are assembled to produce a polymer... inserted b. a polymer breaks up to form monomers... inserted c. monomers are assembled to produce a polymer... produced d. a polymer breaks up to form monomers... produced 34. The molecular formula of most monosaccharides represents a multiple of a. CH3O. b. CH2O. c. CHO. d. CHO2. 35. Which of the following statements about glucose is true? a. Glucose is a disaccharide composed of two glucose molecules. b. Glucose is a monosaccharide that serves as a primary source of energy for cells. c. Glucose is a complex carbohydrate made up of long chains of sugar units. d. Glucose is found only in animal tissues and not in plants. e. Two of the above are true. 36. A linear trisaccharide made from glucose has the formula: a. C18H36O18 b. C18H34O17 c. C18H32O16 d. C18H30O15 37. The typical American consumes more than the FDA recommended daily allowance of added sugar, even though high sugar intake has been correlated with adverse health effects. a. True b. False 38. In plants, __________ is a storage form of carbohydrate, while __________ is a structural form. a. starch; glycogen b. glycogen; starch c. cellulose; starch d. starch; cellulose 39. Which of the following statements correctly distinguishes between chitin and glycogen? a. Chitin is a polysaccharide found in the cell walls of plants, while glycogen is a polysaccharide stored in animal tissues. b. Chitin is a structural polysaccharide found in the exoskeletons of arthropods and the cell walls of fungi, while glycogen is a storage polysaccharide found in animal tissues. c. Chitin is a type of sugar found in fruits, while glycogen is a type of protein found in muscles. d. Chitin and glycogen are both used primarily for energy storage in plants. 1. The molecule below is a(n):  a. nucleotide. b. triglyceride. c. monosaccharide. d. amino acid. 2. What feature of fats makes them hydrophobic? a. Fats have carboxyl groups. b. Fats have nonpolar hydrocarbon chains. c. Fats have polar fatty acids. d. Fats include one glycerol molecule. 3. A diet high in animal products and hydrogenated vegetable margarine may increase the risk for heart disease. This is because: a. most animal fats are used for energy storage and most hydrogenated vegetable margarines contain high levels of unsaturated fats. b. most animal fats are unsaturated and most hydrogenated vegetable margarines contain high levels of steroids. c. most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats. d. most hydrogenated vegetable margarines are hydrogenated oils and most animal products contain high levels of phospholipids. 4. You have a cup of vegetable oil and a vial full of normal phospholipids. What would you predict would happen if you dropped the phospholipids into the cup of vegetable oil? a. The phospholipids would float on the surface of the oil with the heads in the air. b. The phospholipids would float on the surface of the oil with the tails in the air. c. The phospholipids would form a sphere with the tails on the outside. d. The phospholipids would form a sphere with the heads on the outside. 5. Which statement about anabolic steroids is NOT true? a. They cause a general buildup of muscle mass. b. They often cause the body to reduce its normal output of sex hormones. c. They promote bone growth. d. They can stimulate mood swings and violent behavior. 6. Which molecule would be correctly classified as a protein? a. cholesterol b. guanine c. an enzyme d. cellulose 7. Denaturation of a protein does NOT affect its function. a. True b. False 8. Amino acids can be distinguished from one another by: a. the chemical properties of their amino and carboxyl groups. b. the chemical properties of their R groups. c. the number of R groups found on the amino acid molecules. d. the type of bond between the R group and the rest of the amino acid molecule. e. Two of the above are correct. 9. A peptide bond forms when the carboxyl group of one amino acid joins with the __________ group of another amino acid in a __________ reaction. a. carboxyl: hydrolysis b. amino: dehydration c. carbonyl; hydrolysis d. amino: hydrolysis e. carboxyl: dehydration 10. The hydroxyl group in the R group of the amino acid below is __________, thus this amino acid would likely be found __________ of a cytosolic protein. a. nonpolar; in the center b. polar; on the surface c. nonpolar; on the surface d. polar; in the center 11. Which phrase describes a type of secondary structure in a protein? a. a particular amino acid sequence b. an alpha helix c. a globular shape d. the joining of two polypeptide chains 12. Which statement correctly describes bonds of the tertiary structure of proteins? a. Diphosphate bridges form at the tertiary level. b. Tertiary structure involves the association of polypeptide chains, or subunits. c. Tertiary structure involves bonding between atoms of the R groups of the amino acid subunits. d. Tertiary structure involves hydrogen bonding between atoms of the polypeptide backbone. 13. A DNA nucleotide is composed of a __________. a. ribose sugar, which is attached to a phosphate group, which is bonded to a nitrogenous base b. ribose sugar, which is bonded to both a phosphate group and a nitrogenous base c. deoxyribose sugar, which is attached to a phosphate group, which is bonded to a nitrogenous base d. deoxyribose sugar, which is bonded to a phosphate group and a nitrogenous base 14. What is the DNA sequence complementary to the DNA strand TCGATGG? a. TCGATGG b. GGTAGCT c. AGCUACC d. AGCTACC 15. Which of the following “flows of information” is correct? a. DNA to protein to RNA b. RNA to DNA to protein c. Protein to RNA to DNA d. RNA to protein to DNA e. DNA to RNA to protein 16. People with lactose intolerance are unable to: a. digest milk proteins. b. produce lactose. c. produce lactase. d. digest lactose. e. Two of the above are correct. 17. Why did the lactose tolerance mutation in northern Europeans spread so rapidly within the population? a. Milk provided calcium for strong bones. b. It was a selective advantage for survival during droughts and cold winters. c. Lactose was a better source of energy than cellulose. d. Milk was a good source of protein during the summer harvests. 18. Resolution is the: a. ability of an optical instrument to magnify an image. b. ability of an optical instrument to show two close objects as separate. c. distance between the lenses of a microscope. d. size of an image. 19. A scanning electron microscope is used to study ________, whereas a transmission electron microscope is used to study ________. a. live cells; dead cells b. cell surfaces; internal cell structures c. dead cells; live cells d. internal cell structures; cell surfaces 20. A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation: a. will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will increase more quickly than its cytoplasmic needs. b. should present no problem to the cell, since it can continue to perform all other necessary functions. c. will eventually be problematic, because the increase in the volume of the cell will be greater than the increase in the surface area of the cell. d. should be beneficial, since the cell will be able to divert the ATP normally used for cell division to other processes. 21. In the plasma membrane, the phospholipid heads: a. are hydrophilic and face outward toward the aqueous solution on both sides of the membrane. b. are hydrophilic and face inward, shielded from water. c. are hydrophobic and face outward toward the aqueous solution on both sides of the membrane. d. are hydrophobic and face inward, shielded from water. 22. A cell pictured in an electron micrograph image has a cell wall and ribosomes. You conclude correctly that the cell: a. is a plant cell. b. is an animal cell. c. is a bacterial cell. d. could be either a plant or bacterial cell. 23. Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic? a. the presence or absence of a nucleus b. the presence or absence of ribosomes c. the presence or absence of a rigid cell wall d. the presence or absence of RNA e. Two of the above are correct. 24. The nucleus contains DNA and the __________, where __________ occurs. a. nucleoid; translation b. nucleolus; translation c. nucleoid; ribosome assembly d. nucleolus; ribosome assembly 25. Protein synthesis requires the use of mRNA, which: a. is made in the nucleolus. b. must be made by the ribosomes. c. is translated by the ribosomes into the amino acid sequences of proteins. d. carries the message to the nucleus to synthesize new DNA during cell division. 26. Proteins modified in the Golgi apparatus might be carried to lysosomes in transport vesicles. a. True b. False 27. Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which list correctly orders the structures through which insulin passes, from its production to its exit from the cell? a. rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane b. rough ER, lysosomes, transport vesicles, cell membrane c. rough ER, Golgi apparatus, smooth ER, cell membrane d. rough ER, transport vesicles, Golgi apparatus, vacuole, cell membrane 28. Which of the following is a function of the rough endoplasmic reticulum? a. Calcium ion storage in muscle cells b. Detoxification of harmful substances in liver cells c. Lipid synthesis d. Secretory protein synthesis e. Two of the above are correct. 29. Proteins and membrane produced by the smooth endoplasmic reticulum might be carried to the Golgi apparatus by transport vesicles. a. True b. False 30. The Golgi apparatus: a. is composed of stacks of membranous vesicles that are continuous with one another. b. modifies and packages proteins. c. strings together amino acids to produce proteins. d. is the site of carbohydrate breakdown. 31. In the lysosome, many different types of organic matter is degraded. For example, nucleases and proteases in the lysosome degrade nucleic acids and proteins, respectively. The resulting products of digestion, such as nucleotides and amino acids, are transported into the cytosol for re-use. a. True b. False 32. A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they: a. have lost water and shrunk. b. have gained water and burst. c. have died of malnutrition. d. have died because wastes have built up in the cytoplasm. 33. Which cell structures are associated with the breakdown of harmful substances? a. chloroplasts b. mitochondria c. peroxisomes d. centrosomes 34. Mitochondria and chloroplasts are similar in that they both __________; however, they are different in that only chloroplasts, and NOT mitochondria, __________. a. deal with energy transformations … are found only in eukaryotes b. have a double membrane … carry out photosynthesis c. have an internal 9 + 2 arrangement of microtubules … also have centrioles d. have many internal membranes that increase their internal surface area … are found in animals 35. Chloroplasts differ from mitochondria in that chloroplasts: a. convert one form of chemical energy to another, whereas mitochondria convert light energy from the sun to chemical energy. b. contain three different membrane-bound compartments, whereas mitochondria contain two. c. contain membrane folds called cristae, whereas mitochondria contain disk-like vesicles in stacks called grana. d. are not found in animals, whereas mitochondria are not found in plants. 36. Which part of the mitochondrion shown below contains DNA? a. Structure A b. Structure B c. Structure C d. Structure D e. None of the above 37. The origin of __________ is believed to be the result of the engulfment of a(n) __________ bacterium by an ancestor of eukaryotic cells. a. chloroplasts; oxygen-using b. chloroplasts; photosynthetic c. mitochondria; oxygen-using d. mitochondria; photosynthetic e. Both b and c are correct. 38. Microtubules differ from microfilaments in that microtubules: a. are mainly composed of actin, whereas microfilaments are composed of tubulin. b. are thicker than microfilaments. c. are found only in plants, whereas microfilaments are found in both plant and animal cells. d. protect cells from stretching forces, whereas microfilaments primarily function to help cells change shape and move. 39. A woman is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein feet are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by: a. interfering with the attachment of the flagella to the sperm. b. preventing the sperm from attaching to the egg cell. c. preventing the sperm from producing enough energy to power swimming. d. preventing the sperm from swimming to the egg cell. 40. __________ are membrane-spanning proteins that interact with both the __________ matrix and the cytoskeleton. a. Integrins; extracellular b. Microfilaments; extracellular c. Integrins; intracellular d. Microfilaments; intracellular 41. Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? a. The intestinal cells are bound together by gap junctions. b. The intestinal cells are bound together by plasmodesmata. c. The intestinal cells are bound together by tight junctions. d. The intestinal cells are fused together into one giant cell. 42. The plant cell wall, which is primarily composed of cellulose, provides cell support that helps keep land plants upright. a. True b. False