1. Which is the smallest unit of life that can exist as a separate entity?
A. a cell
B. a molecule
C. an organ
D. a population
E. an ecosystem
2. The conversion of solar energy to chemical energy is known as
A. metabolism.
B. photosynthesis.
C. chemosynthesis.
D. catabolism.
E. anabolism.
3. All organisms are alike in
A. their requirements for energy.
B. their participation in one or more nutrient cycles.
C. their ultimate dependence on the sun.
D. their interaction with other forms of life.
E. all of the above
4. Which of the following is NOT a eukaryote?
A. fungi
B. bacteria
C. plants
D. animals
E. protistans
5. As a result of experimentation,
A. more hypotheses may be developed.
B. more questions may be asked.
C. a new biological principle could emerge.
D. entire theories may be modified or discarded.
E. all of the above
6. Four of the five answers listed below are terms associated with the scientific method. Select the exception.
A. fact
B. theory
C. experiment
D. prediction
E. hypothesis
7. Which includes the other four?
A. atoms
B. molecules
C. electrons
D. elements
E. protons
8. The atomic number refers to the
A. mass of an atom.
B. number of protons in an atom.
C. number of both protons and neutrons in an atom.
D. number of neutrons in an atom.
E. number of electrons in an atom.
9. The nucleus of an atom contains
A. neutrons and protons.
B. neutrons and electrons.
C. protons and electrons.
D. protons only.
E. neutrons only.
10. Radioactive isotopes have
A. excess electrons.
B. excess protons.
C. excess neutrons.
D. insufficient neutrons.
E. insufficient protons.
11. Magnesium has twelve protons. How many electrons are in its third energy level?
A. 2
B. 4
C. 6
D. 8
E. 10
12. Nitrogen has an atomic number of 7. How many hydrogen atoms are necessary to join with the nitrogen to form a stable compound?
A. 1
B. 2
C. 3
D. 4
E. 5
13. What is formed when an atom loses or gains an electron?
A. mole
B. ion
C. molecule
D. bond
E. reaction
14. The bond in table salt (NaCl) is
A. polar.
B. ionic.
C. covalent.
D. double.
E. nonpolar.
15. In __________ bonds, both atoms exert the same pull on shared electrons.
A. nonpolar covalent
B. polar covalent
C. double covalent
D. triple covalent
16. Which of the following is NOT true of hydrogen bonds?
A. They are quite weak.
B. The hydrogen is slightly positive.
C. They are common in macromolecules.
D. They form in salts such as NaCl.
E. They always involve hydrogen.
17. Hydrophobic molecules are __________ water.
A. attracted to
B. absorbed by
C. repelled by
D. mixed with
E. polarized by
18. In a lipid bilayer, the __________ phospholipid tails point inward and form a region that excludes water.
A. acidic
B. basic
C. hydrophilic
D. hydrophobic
E. none of the above
19. A pH of 10 is how many times as basic as a pH of 7?
A. 2
B. 3
C. 10
D. 100
E. 1,000
20. Cellular pH is kept near a value of 7 because of
A. salts.
B. buffers.
C. acids.
D. bases.
E. water.
21. Carbon usually forms how many bonds with other atoms?
A. 2
B. 3
C. 4
D. 5
E. 6
22. The formation of large molecules from small repeating units is known as what kind of reaction?
A. oxidation
B. reduction
C. condensation
D. hydrolysis
E. decarboxylation
23. Fructose and glucose are
A. isotopes.
B. monosaccharides.
C. disaccharides.
D. six-carbon sugars.
E. both b and d, but not a or c
24. Which of the following cannot be used to describe some aspect of polysaccharides?
A. energy storage
B. straight or branched chain
C. glucose subunits
D. insoluble in water
25. Which of the following are lipids?
A. sterols
B. triglycerides
C. oils
D. waxes
E. all of the above
26. Plasma membranes are characterized by the presence of
A. triglycerides.
B. phospholipids.
C. unsaturated fats.
D. steroids.
E. fatty acids.
27. Amino acids are the building blocks for
A. proteins.
B. steroids.
C. lipids.
D. nucleic acids.
E. carbohydrates.
28. The interaction of four polypeptide chains in a hemoglobin molecule is __________ structure.
A. quaternary
B. secondary
C. primary
D. tertiary
E. quintinery
29. Which molecule is incorrectly matched with its component parts?
A. fat: fatty acids
B. starch: riboses
C. protein: amino acids
D. glycogen: glucoses
E. nucleic acids: nucleotides
30. Which of these cell features is absent in a bacterial cell?
A. plasma membrane
B. nucleoid
C. cytoplasm
D. nucleus
E. DNA
31. If the volume of a cell increases, its surface area will
A. decrease.
B. remain the same.
C. increase proportionately.
D. increase to a greater degree.
E. increase to a lesser degree.
32. Which of the following organelles is correctly matched with its function?
A. nucleus: protein synthesis
B. ER: heredity
C. Golgi bodies: packaging
D. mitochondria: digestion
E. chloroplasts: storage of lipids
33. The breakdown of a plasma or nuclear membrane would yield
A. cellulose.
B. suberin and cutin.
C. phospholipids and proteins.
D. microtubules and microfilaments.
34. Which of the following are the primary structures for the packaging of cellular secretions for export from the cell?
A. Golgi bodies
B. ribosomes
C. mitochondria
D. lysosomes
E. endoplasmic reticula
35. Which of the following contain enzymes and are the main organelles of intracellular digestion?
A. Golgi bodies
B. ribosomes
C. mitochondria
D. lysosomes
E. endoplasmic reticula
36. Which of the following contain enzymes used in the breakdown of glucose and generation of ATP?
A. Golgi bodies
B. ribosomes
C. mitochondria
D. lysosomes
E. endoplasmic reticula
37. Four of the five statements listed below are portions of a well-known theory. Select the exception.
A. Cells are the structural and functional components of living things.
B. Cells arise from preexisting cells.
C. All organisms are composed of cells.
D. Cells are the basic living unit of organization of living things.
E. All cells have a nucleus.
38. Four of the five answers listed below are bound by membranes. Select the exception.
A. mitochondrion
B. ribosome
C. chromoplast
D. vacuole
E. lysosome
39. Unsaturated tails of lipids
A. are hydrophilic.
B. are unstable and tend to break apart.
C. have kinks in them and lessen the interaction between adjacent fat molecules.
D. will break whenever exposed to phosphate ions.
E. all of the above
40. The relative impermeability of membranes to water-soluble molecules is a result of
A. the nonpolar nature of water molecules.
B. the presence of large proteins that extend through both sides of membranes.
C. the presence of inorganic salt crystals scattered through some membranes.
D. the presence of cellulose and chemicals such as cutin, lignin, pectin, and suberin in the membranes.
E. the presence of phospholipids in the lipid bilayer.
41. A membrane is more "fluid" than solid because
A. phospholipid tails prevent close packing.
B. proteins can shift positions.
C. water is the main component.
D. a and b only
E. a, b, and c
42. A concentration gradient ceases to exist when
A. all the molecules have moved from high concentration to low.
B. the membrane pores close.
C. the temperature drops.
D. there is no net movement.
E. bulk flow intervenes.
43. A single-celled freshwater organism, such as a protistan, is transferred to saltwater. Which of the following is likely to happen?
A. The cell bursts.
B. Salt is pumped out of the cell.
C. The cell shrinks.
D. Enzymes flow out of the cell.
E. all of the above
44. Movement of a molecule against a concentration gradient is
A. simple diffusion.
B. facilitated diffusion.
C. osmosis.
D. active transport.
E. bulk flow.
45. The second law of thermodynamics states that
A. energy can be transformed into matter and, because of this, we can get something for nothing.
B. energy can be destroyed only during nuclear reactions, such as those that occur inside the sun.
C. if energy is gained by one region of the universe, another place in the universe also must gain energy in order to maintain the balance of nature.
D. energy tends to become increasingly more disorganized.
E. none of the above
46. Essentially, the first law of thermodynamics says that
A. one form of energy cannot be converted into another.
B. entropy is increasing in the universe.
C. energy can be neither created nor destroyed.
D. energy cannot be converted into matter or matter into energy.
E. all of the above
47. Which of the following statements is NOT true?
A. At an equilibrium there are equal numbers of molecules on each side of a reaction.
B. Chemical equilibrium is controlled solely by the amount of the reactants available.
C. A chemical equilibrium is reached when the forward and reverse reactions occur at the same rate.
D. both a and b are not true, but c is true
E. a, b, and c are not true
48. Which of the following statements is false?
A. Enzymes catalyze reversible reactions in either direction.
B. Enzymes are highly specific.
C. Most enzymes are protein molecules.
D. Enzymes allow some reactions to occur that would never occur without their help.
E. Although enzymes may be modified during their involvement with the substrate, they revert back to their original characteristics when the reaction is over.
49. Enzymatic reactions can be controlled by
A. the amount of substrates available.
B. the concentration of products.
C. temperature.
D. modification of reactive sites by substances that fit into the enzyme and, later, their reactive site.
E. all of the above
50. The removal of electrons from a compound is known as
A. dehydration.
B. oxidation.
C. reduction.
D. phosphorylation.
E. a nonreversible chemical reaction.