Review Cell Biology PDF

All the chemical reactions that occur in a cell are called a. metabolism. b. homeostasis. c. heterostasis. d. cytoplasm. 2. A modification that helps equip organisms for their way of life is a(n) a. adaptation. b. homeostasis. c. natural selection. d. extinction. 3. The proce...

All the chemical reactions that occur in a cell are called a. metabolism. b. homeostasis. c. heterostasis. d. cytoplasm. 2. A modification that helps equip organisms for their way of life is a(n) a. adaptation. b. homeostasis. c. natural selection. d. extinction. 3. The process of turning solar energy into chemical energy is called a. photosynthesis. b. work. c. metabolism. d. respiration. 4. Which of the following is not a theme that unifies biology?  a. reductionism b. evolution c. structure and function d. emergent properties 5. Protist and bacteria are grouped into different domains because a. protists have a membrane-bound nucleus. b. protists eat bacteria. c. bacteria are not made of cells. d. protists are photosynthetic. 6. Which of the following best demonstrates the unity among all organisms? a. the structure and the function of DNA b. emergent properties c. descent with modification d. natural selection 7. In terms of the hierarchical organization of life, a bacterium is at the \_\_\_(1)\_\_\_\_\_ level of organization, whereas a human is at the \_\_(2)\_\_\_\_ level of organization. a\) (1) single-celled organism; (2) multicellular organism b\) (1) single organelle; (2) organism c\) (1) organelle; (2) organ system d\) (1) tissue; (2) organism 8. The main source of energy for producers in an ecosystem is a. light energy b. kinetic energy c. ATP d. chemical energy 9. The lowest level of biological organization that can perform all the activities required for life is the a. cell - for example, a skin cell. b. organelle - for example, a chloroplast. c. tissue - for example, nervous tissue. d. organism - for example, a dog, human, or a tree. 10. Which of the following statements concerning prokaryotic and eukaryotic cells is ***[not correct]***? a. Prokaryotic cells contain small membrane-enclosed organelles. b. Eukaryotic cells contain a membrane-bound nucleus. c. DNA is present in both prokaryotic and eukaryotic cells. d. Prokaryotic cells lack a membrane-bound nucleus. 11. Prokaryotic and eukaryotic cells generally have which of the following features in common? a. ribosomes b. a membrane-bound nucleus c. a cell wall made of cellulose d. linear chromosomes made of DNA and protein 12. Anton van Leeuwenhoek made an important contribution to the development of the cell theory. How? a. He invented more powerful microscopes and was the first to describe the diversity of cells. b. He articulated the pattern component of the theory - that all organisms are made of cells. c. He articulated the process component of the theory - that all cells come from preexisting cells. d. He invented the first microscope and saw the first cell. 13. Which of these provide evidence of the common ancestry of all life? a. the universality of the genetic code b. the structure of the nucleus c. the structure of chloroplasts d. the ubiquitous use of catalysts by living system 14. A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is most likely classification? a. Archaea b. Protista c. Eukarya d. Fungi 15. Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? a. nervous system, brain, nervous tissue, nerve cell b. brain, organ system, nerve cell, nervous tissue c. organ system, nervous tissue, brain d. organism, organ system, tissue, cell, organ 16. If the reaction is exothermic, then which of the following statements is ***[true]***? a. The products have a lower potential energy than the reactants. b. Energy must be added for the reaction to proceed. c. The products have lower entropy (are more ordered) than the reactants. d. It occurs extremely quickly. 17. In the term trace element, the adjective trace means that a. the element is required in very small amounts. b. the element can be used as a label to trace atoms through an organism's metabolism. c. the element is very rare on Earth. d. the element enhances health but is not essential for the organism\'s long-term survival. 18. The atomic mass of an atom depends on the number of ­­­ a. protons and neutrons.  b. positrons. c. neutrons and electrons. d. protons and electrons. 19. Which of the following is most likely to have been the energy source responsible for the formation of acetic acid in deep-sea hydrothermal vents? a. chemical energy present in the reactants. b. heat released from the vents. c. solar radiation that passed through the ocean water. d. the increase in entropy in the products. 20. What is thermal energy? a. the kinetic energy of molecular motion, measured as heat b. a form of potential energy c. the temperature increase that occurs when any form of energy is added to a system d. mechanical energy 21. Which of the following molecules would you predict to have the largest number of polar covalent bonds based on their molecular formulas? a. C~2~H~4~O~2~ (acid acetic) - CH~3~COOH b. C~2~H~6~O (ethanol) - C~2~H~5~OH c. C~2~H~6~ (ethane) d. C~3~H~8~O (propanol) - C~3~H~7~OH 22. Which of the following occurs when a covalent bond forms? a. Electrons in valence shells are shared between nuclei. b. The potential energy of electrons drops. c. Ions of opposite charges interact. d. Polar molecules interact. 23. Compared with ^31^P, the radioactive isotopitttttt†††ttttttttttttttttte ^32^P has a. one more neutron. b. one more electron. c. one more proton. d. a different atomic number. 24. The reactivity of an atom arises from a. the existence of unpaired electrons in the valence shell. b. the average distance of the outermost electron shell from the nucleus. c. the sum of the potential energies of all electron shells. d. the potential energy of the valence shell. 25. Which statement is ***[true]*** of all atoms that are anions? a. The atom has more electrons than protons. b. The atom has more protons than electrons. c. The atom has fewer protons than does a neutral atom of the same element. d. The atom has more neutrons than protons. 26. Which of the following statements correctly describes any chemical reaction that has reached equilibrium? a. The rates of the forward and reverse reactions are equal.  b. The concentration of products and reactants are equal. c. The reaction is now irreversible. d. Both forward and reverse reactions have halted. 27. The most abundant element by weight in the human body is a. oxygen. b. carbon. c. hydrogen. d. nitrogen. 28. A covalent bond in which electrons are not shared equally is called a. polar. b. normal. c. nonpolar. d. neutral. 29. Water flows freely but does not separate into individual molecules because water is a. cohesive. b. hydrophilic. c. hydrophobic. d. adhesive. 30. Water freezes from the top down because a. ice is less dense than water. b. water has a high surface tension. c. ice has a high heat capacity. d. ice is less cohesive than water. 31. Water can absorb a large amount of heat without much change in temperature because it has a high a. heat capacity. b. surface tension. c. hydrogen ion (H^+^) concentration. d. hydroxide ion (OH^-^) concentration. 32. A solution has a large amount of hydrogen ion (H^+^) dissociated into it; which of the following will act as a buffer to this solution? a. OH^-^ b. H^+^ c. NaOH d. HCl 33. What two functional groups are present on every amino acid? a. an amino group and a carboxyl group b. a carbonyl (C=O) group and a carboxyl group c. an N-H group and a carbonyl group d. an amino group and a hydroxyl group 34. In a polypeptide, what bonds are responsible for the secondary structure called an alpha helix? a. hydrogen bonds that form between the core C=O and N-H groups on different residues. b. peptide bonds c. hydrogen bonds and other interactions between side chains  d. disulfide bonds that form between cysteine residues 35. What are the four nitrogenous bases found in RNA? a. adenine, uracil, guanine, cytosine (A, U, G, C) b. thymine, uracil, guanine, cytosine (T, U, G, C) c. adenine, thymine, guanine, cytosine (A, T, G, C) d. alanine, threonine, glycine, cysteine (A, T, G, C) 36. What is the difference between a monosaccharides, oligosaccharide, and a polysaccharide? a. the number of monomers in the molecule b. the number of carbon atoms in the molecule c. the type of glycosidic linkage between monomers d. the spatial arrangement of the various hydroxyl residues in the molecule 37. What distinguishes amphipathic lipids from other lipids? a. Amphipathic lipids have polar and nonpolar regions. b. Amphipathic lipids have saturated and unsaturated regions. c. Amphipathic lipids are steroids. d. Amphipathic lipids dissolve in water 38. Carbon chain can vary in a. length, number of double bonds, and branching pattern. b. length and number of double bonds. c. number of double bonds and branching pattern. d. length and branching pattern. 39. Organic molecules containing carboxyl group are a. acidic b. nonpolar c. basic d. polar 40. Biological macromolecules are polymers that are formed when \_\_\_\_\_(1)\_\_\_\_\_ are joined by a \_\_\_\_\_(2)\_\_\_\_\_ reaction. a. monomers, (2) dehydration synthesis b. multimers, (2) dehydration synthesis c. subunits, (2) reduction d. monomers, (2) hydrolysis reactions 41. Which of the following is a monosaccharide? a. glucose b. cellulose c. lactose d. sucrose 42. Cellulose, the major component of plant cell walls, is a a. carbohydrate. b. lipid. c. protein. d. nucleic acid. 43. Keratin - found in hair, fingernails, horns, and feathers - is a a. protein. b. carbohydrate. c. lipid. d. nucleic acid. 44. Variation in three-dimensional shapes among proteins are due to bonding between the a. R groups. b. amino groups. c. ion groups. d. H atoms. 45. Cholesterol is the precursor of a. testosterone and estrogen. b. glucose and estrogen. c. lipid and testosterone. d. protein and estrogen. 46. Which of the following lipids would most likely be solid at room temperature? a. palmitic acid, a saturated fatty acid b. oleic acid, an unsaturated fatty acid c. cholesterol, a steroid d. elaidic acid, a trans fat 47. Galactosemia is a potentially fatal disease that occurs in humans who lack the enzyme that converts galactose to glucose. To treat this disease, physicians exclude the monosaccharide galactose from the diet. Which of the following would you also predict to be excluded from the diet? a. lactose b. maltose c. starch d. mannose 48. How would you expect the structure of ribozyme in organisms that grow in very hot environments, such as hot springs or deep-sea vents, to differ from those in organisms that grow in cooler environments? a. The hairpins would have more G's and C's in the primary structure. b. These ribozymes would have more hairpin secondary structures. c. The hairpins would have more A's and T's in the primary structure. d. These ribozymes would exhibit no tertiary structure. 49. Proteins that interact with DNA often interact with the phosphates that are part of this molecule. Which of the following types of amino acids would you predict to be present in the DNA binding sites of these proteins? a. basic amino acids b. acidic amino acids c. uncharged polar amino acids d. nonpolar amino acids 50. If nucleotides from the DNA of a human were quantified and 30 percent of them consisted of adenine, what percentage of guanine nucleotides would be present? a. 20 percent b. 30 percent c. 40 percent d. 70 percent 57\. Which of the following is not found in a prokaryotic cell? a. mitochondria b. cytoplasm c. ribosomes d. plasma membrane 58\. Which of the following can be viewed only with an electron microscope? a. virus b. chloroplast c. bacterium d. human egg 59\. The plasma membrane is called a fluid mosaic because it contains a. a mosaic of proteins suspended within a phospholipid bilayer. b. waxes suspended within a mosaic of pho c. spholipids. d. a polysaccharide mosaic suspended within a protein bilayer. e. a mosaic of phospholipids suspended within a protein bilayer. 60\. The organelle that sorts proteins and sends them to their final destinations is the a. Golgi apparatus. b. ribosome. c. vacuole. d. lysosome. 61\. Which of these structures is involved in protein synthesis? a. ribosomes b. plasma membrane c. mitochondria d. microtubules 62\. Identify the ***[incorrect]*** statement. a. A light microscope allows us to see cells and their inner complexity. b. A bacterial cell can contain thousands of ribosomes. c. In both eukaryotes and prokaryotes, the plasma membrane is a phospholipid bilayer. d. A receptor protein has a special shape that allows a signal molecule to bind to it. 63\. Eukaryotic cells compensate for a low surface-to-volume ratio by a. compartmentalizing their activities into organelles. b. taking up materials from the environment more efficiently. c. lowering their rate of metabolism. d. reducing the number of activities in each cell. 64\. Ribosomal subunits are produced in which organelle? a. nucleolus b. mitochondria c. endoplasmic reticulum d. cytoplasm 65\. Which of the following accurately describes a difference between prokaryotic and eukaryotic cells? a. Eukaryotic cells are generally larger than prokaryotic cells. b. Prokaryotic cells have fimbriae that allow the cell to swim whereas eukaryotic cells have flagella. c. Eukaryotic cells have organelles. d. Prokaryotic cells have nuclei and eukaryotic cells have nucleoids. 66\. Which of the following is ***[not true]*** of secreted proteins? a. They contain a signal that directs them into the lysosome. b. They are synthesized using ribosomes. c. They enter the endoplasmic reticulum lumen during translation. d. They are transported between organelles in membrane-bound vesicles. 67\. Which of the following cell structures would you expect to be the most important in the growth of bacteria on the surface of your teeth? a. fimbriae b. cell wall c. flagella d. cilia 68\. Which of the following is a major cause of the size limits for certain types of cells? a. the need for a surface area of sufficient area to allow the cell's function b. the evolution of larger cells after the evolution of smaller cells c. the difference in plasma membranes between prokaryotes and eukaryotes d. the observation that longer cells usually have greater cell volume 69\. Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids? a. smooth endoplasmic reticulum b. ribosome c. lysosomes d. contractile vacuole 70\. The liver is involved in detoxification of many poisons and drugs. Which of the following structure is primarily involved in this process and therefore abundant in liver cells? a. smooth endoplasmic reticulum b. rough endoplasmic reticulum c. Golgi apparatus d. Transport vesicle 71\. How does the cell multiply its peroxisomes? a. They split in two after they are too large. b. They are brought into the cell from the environment. c. They bud off from the endoplasmic reticulum. d. The cell synthesizes hydrogen peroxide and encloses it in a membrane. 72\. Large number of ribosomes are present in cells that specialize in producing which of the following molecules? a. proteins b. lipids c. glucose d. starches 73\. Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read? a. They bind to receptor proteins. b. They enter transport vesicles. c. They bind to motor proteins. d. They are glycosylated by enzymes in the Golgi apparatus. 75\. Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes? a. a cell that is producing cytoplasmic enzymes b. a cell that is secreting proteins c. a cell that is digesting food particles d. a cell that is constructing its cell wall or extracellular matrix 76\. Which of the following statements correctly describes some aspects of protein disposal from prokaryotic cells? a. Proteins that are excreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. b. The mechanism of protein excretion in prokaryotes is probably the same as that in eukaryotes. c. In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside the cell. d. Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell. 77\. Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? a. the lysosome b. the endoplasmic reticulum c. the Golgi apparatus d. mitochondria 78\. Why isn't the mitochondrion classified as part of the endomembrane system? a. Its structure is not derived from the endoplasmic reticulum. b. It only has two membrane layers. c. It is not involved in protein synthesis. d. It is not attached to the outer nuclear envelope. 79\. The peroxisome gets its name from its interaction with hydrogen peroxide. If a liver cell is detoxifying alcohol and some other poisons, it does so by removal of hydrogen from the molecules. What, then, do the enzymes of the peroxisome do? a. transfer the hydrogens to oxygen molecules b. combine the hydrogen with ATP c. use the hydrogen to breakdown hydrogen peroxide d. transfer the harmful substances to the mitochondria 80\. The cell wall of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic of all of these extracellular structures? a. They are constructed of materials that are largely synthesized in the cytoplasm and then transported out of the cell.  b. They must block water and small molecules in order to regulate the exchange of matter and energy with their environment. c. They must permit information transfer between the cell's cytoplasm and the nucleus. d. They are composed of a mixture of lipids and carbohydrates. 82\. Of the following functions, which is the most important for the glycoproteins and glycolipids of animal cell membranes? a. a cell's ability to distinguish one type of neighboring cell from another b. facilitated diffusion of molecules down their concentration gradient c. active transport of molecules against their concentration gradient d. maintaining the integrity of a fluid mosaic membrane 83\. What kinds of molecules pass through a cell membrane most easily?  a. small and hydrophobic b. large polar c. ionic d. monosaccharides such as glucose 84\. Water passes quickly through cell membranes because a. it moves through aquaporins in the membrane. b. the bilayer is hydrophilic. c. it moves through hydrophobic channels. d. it is a small, polar, charged molecule. 85\. The sodium-potassium pump is called an electrogenic pump because it a. contributes to the membrane potential. b. pumps equal quantities of Na+ and K+ across the membrane. c. ionizes sodium and potassium atoms. d. is used to drive the transport of other molecules against the concentration gradient. 86\. A cell specializing in endocytosis would likely have many a. lysosomes. b. nuclei. c. mitochondria. d. aquaporins. 87\. A coated pit is associated with a. receptor-mediated endocytosis. b. simple diffusion. c. osmosis. d. pinocytosis. 88\. Movement of molecules from high concentration to low concentration include a. Simple diffusion, Facilitated diffusion, Osmosis b. Facilitated diffusion, Osmosis, Active transport c. Osmosis, Active transport, Simple diffusion d. Active transport, Simple diffusion, Facilitated diffusion 89\. Cells involved in active transport have a large number of \_\_\_\_\_\_\_\_\_\_\_\_ near their plasma membrane. a. mitochondria b. vacuoles c. actin filaments d. aquaporins 90\. Seawater is nearly \_\_\_\_\_(1)\_\_\_\_\_\_\_ to blood because it contains a(n) \_\_\_\_(2)\_\_\_\_\_ concentration of solutes. a. isotonic, (2) equal b. isotonic, (2) higher c. hypotonic, (2) higher d. hypertonic, (2) lower 91\. If a solution surrounding a cell is hypertonic relative to the inside of a cell, how will water move? a. It will move out of the cell via osmosis. b. It will move into the cell via osmosis. c. It will not move, because equilibrium exists. d. It will evaporate from the cell surface more rapidly. 92\. When does a concentration gradient exist? a. when solute concentrations differ on the two sides of a membrane b. when membrane rupture c. when solute concentrations are high d. when solute concentrations are low 93\. The difference between pinocytosis and receptor-mediated endocytosis is that a. pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well. b. pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the surface area of the plasma membrane.  c. pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. d. pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot. 94\. Mechanisms by which glucose enters cells is a. Facilitated diffusion  b. Simple diffusion c. Osmosis d. Active transport 95\. Which of the following types of transport required a protein pump? a. Active transport  b. Facilitated diffusion c. Osmosis d. Simple diffusion 96\. Which of the following types of transport required a membrane. a. Facilitated diffusion, Osmosis, Active transport  b. Simple diffusion, Facilitated diffusion, Osmosis c. Osmosis, Active transport, Simple diffusion d. Active transport, Simple diffusion, Facilitated diffusion 97\. In an experiment, you create two groups of liposomes - one made from red blood cell membranes and the other from frog egg cell membranes. When placed in water, those made with red blood cell membranes burst more rapidly than those made from frog membranes. What is the best explanation for these results? a. The red blood cell liposomes contain aquaporins, which are not abundant in the frog egg liposomes. b. The red blood cell liposomes are more hypertonic relative to water than the grog egg liposomes. c. The red blood cell liposomes are more hypotonic relative to water than the grog egg liposomes. d. The frog egg liposomes contain ion channels, which are not present in the red blood cell liposomes. 98\. An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function? a. cell-cell recognition b. transporting ions against an electrochemical gradient c. attaching to the cytoskeleton d. establishing the diffusion barrier to charged molecules 99\. After a membrane freezes and then thaws, it often becomes leaky to solutes. The most reasonable explanation for this is that a. the integrity of the lipid bilayer is broken when the membrane freezes. b. the lipid bilayer loses its fluidity when it freezes. c. aquaporins can no longer function after freezing. d. the solubility of most solutes in the cytoplasm decreases on freezing. 100\. You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? a. similarity of the drug molecule to other molecules transported by the target cells b. non-polarity of the drug molecule c. lack of charge on the drug molecule d. lipid composition of the target cells' plasma membrane 101\. Cystic fibrosis is a genetic disease in humans in which chloride ion channels  in cell membranes are missing or nonfunctional. Which of the following would you expect to be a problem for someone with nonfunctional chloride channeling? a. buildup of excessive secretions in organs such as lungs b. inadequate secretion of mucus c. sweat that includes no NaCl d. mental retardation due to low salt levels in brain tissue 102\. Paracrine signaling a. involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid. b. requires nerve cells to release a neurotransmitter into the synapse. c. occurs only in paracrine yeast cells. d. has been found in plants but not animals., 103\. From the perspective of the cell receiving the message, the three stages of cell signaling are \_\_\_\_\_ a. signal reception, signal transduction, and cellular response. b. the paracrine, local, and synaptic stages. c. signal reception, nucleus disintegration, and new cell generation. d. signal reception, cellular response, and cell division. 104\. When a cell releases a signal molecule into the environment and a number of cells in the immediate vicinity respond, this type of signaling is a. paracrine signaling. b. autocrine signaling. c. endocrine signaling. d. synaptic signaling. 105\. A small molecule that specifically binds to another molecule, usually a larger one a. is called a ligand. b. is called a signal transducer. c. seldom is involved in hormonal signaling. d. usually terminates a signal reception. 106\. Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to a. the active site of an allosteric enzyme in the cytoplasm that binds to a specific substrate b. RNA specifying the amino acids in a polypeptide. c. a particular metabolic pathway operating within a specific organelle. d. an enzyme with an optimum pH and temperature for activity. 107\. Membrane receptors that attach phosphates to specific amino acids in proteins are a. called receptor tyrosine-kinases. b. a class of GTP G-protein signal receptors. c. associated with several bacterial diseases in humans. d. important in yeast mating factors that contain amino acids. 108\. Up to 60% of all medicines used today exert their effects by influencing what structures in the cell membrane? a. G-proteins b. tyrosine-kinases receptors c. ligand-gated ion channel receptors d. growth factors 109\. The process of transduction usually begins a. when the signal molecule changes the receptor protein in some way. b. when the chemical signal is released from the alpha cell. c. after the third stage of cell signaling is completed. d. when the hormone is released from the gland into the blood. 110\. In general, a signal transmitted via phosphorylation of a series of proteins a. brings a conformational change to each protein. b. requires binding of a hormone to a cytosol receptor. c. requires phosphorylase activity.  d. allows target cells to change their shape and therefore their activity. 111\. Which of the substances below is a protein that can hold several other relay proteins as it binds to an activated membrane receptor? a. scaffolding protein b. ligand c. third messenger d. active transcription factor 112\. Which of the following describes the events of apoptosis? a. Its DNA and organelles are fragmented, the cell shrinks and forms blends, and the cell self-digests. b. The cell dies, it is lysed, its organelles are phagocytized, its contents are recycled.  c. Its DNA and organelles become fragmented, it dies, and it is phagocytized. d. Its nucleus and organelles are lysed, the cell enlarges and bursts. 113\. A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following? a. a decrease in transcriptional activity of certain genes b. lower cytoplasmic levels of cAMP c. an increase in receptor tyrosine kinase activity  d. an increase in cytosolic calcium concentration 114\. If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to a. design a compound to block G-protein activity in liver cells. b. design a compound that mimics epinephrine and can bind to the epinephrine receptor. c. design a compound that stimulates cAMP production in liver cells. d. design a compound to stimulate G-protein activity in liver cells. 115\. Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consume coffee would have increased levels of a. cAMP. b. GTP. c. adenylyl cyclase. d. activated G proteins. 116\. Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to protein? a. receptor tyrosine kinase activity b. G-protein-linked receptor signaling c. ligand-gated ion channel signaling d. phosphatase activity 117\. The phase following mitosis is a. G1 phase of interphase. b. G2 phase of interphase. c. S phase of interphase. d. G0 phase. 118\. DNA is replicated during a. S phase of interphase. b. G1 phase of interphase. c. G2 phase of interphase. d. G0 phase. 119\. How many chromosomes are in a parent cell entering meiosis? a. diploid number b. haploid number c. two times the diploid number d. three times the haploid number 120\. The spindle begins to assemble during  a. prophase. b. metaphase. c. anaphase. d. interphase. 121\. Plants cannot use a cleavage furrow to undergo cytokinesis because they a. have a cell wall. b. lack a plasma membrane. c. have too many chromosomes. d. are too small. 122\. \_\_\_(1)\_\_\_\_\_ is nuclear division, whereas \_\_\_\_\_(2)\_\_\_\_\_\_\_ is division of the cytoplasm. a. Mitosis, (2) cytokinesis b. Cytokinesis, (2) mitosis c. Apoptosis, (2) mitosis d. Mitosis, (2) apoptosis 123\. Mitosis \_\_\_(1)\_\_\_ chromosome number, whereas meiosis \_\_\_(2)\_\_\_\_\_ the chromosome number of the daughter cells. a. maintains, (2) decreases b. maintains, (2) increases c. increases, (2) maintains d. decreases, (2) maintains 124\. Which cell cycle checkpoint allows damaged DNA to be repaired before it is passed on to daughter cells? a. G2 b. G1 c. S d. miotic 125\. Which of the following is ***[not]*** an event of apoptosis? a. increase the number of mitochondria b. loss of contact with neighboring cells c. blistering of the plasma membrane d. fragmentation of the nucleus 126\. In human beings, mitosis is necessary for a. the growth and repair of tissue, maintenance of the chromosome number in all body cells. b. the formation of gametes, maintenance of the chromosome number in all body cells. c. the growth and repair of tissue, the death of unnecessary cells. d. the death of unnecessary cells, the formation of gametes. 127\. Why cytokinesis in plant cells differs from cytokinesis in animal cells? a. in plant cells, many small vesicles form a cell plate that eventually becomes a new cell wall. b. plant cells form a cleavage furrow that constricts the daughter cells. c. animal cells seldom undergo cytokinesis. d. animal cells divide by the process called binary fission. 128\. Which of the following best describes the attachment of chromosomes to the spindle apparatus during meiosis I? a. The homologous pair lines up together, with homologues facing opposite spindle poles. b. The homologous pair lines up together, with homologues facing the same spindle pole. c. The homologous pair do not line up together, but homologues face opposite spindle poles. d. The homologous pair do not line up together, with homologues facing the same spindle pole. 129\. In which phase of mitosis is evidence of cytokinesis present? a. anaphase and telophase b. prophase and metaphase c. metaphase and anaphase d. telophase and prophase 130\. Which of the following happens at the conclusion of meiosis I? a. Homologous chromosomes are separated. b. The chromosomes number per cell is conserved. c. Sister chromatids are separated. d. Four daughter cells are formed. 131\. Which of the following occurs in meiosis but not in mitosis? a. Synapsis of chromosomes b. Chromosomes replication c. Production of daughter cells d. Alignment of chromosomes at the equator 132\. Rats have 42 chromosomes. How many total chromatids does a rat cell have during the G2 phase? a. 84 b. 42 c. 21 d. 126 133\. Rats have 42 chromosomes. How many total chromatids does a rat cell have during the G1 phase? a. 42 b. 21 c. 84 d. 126 134\. Whether during mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesions. Such molecules must have which of the following properties? a. They must be removed before anaphase can occur. b. They must persist throughout the cell cycle. c. They must reattach to chromosomes during G1. d. They must be intact for nuclear envelope reformation. 135\. Independent assortment of chromosomes is the result of a. the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. b. the random nature of the fertilization of ova by sperm. c. the random distribution of the sister chromatids to the two daughter cells during anaphase II. d. the relatively small degree of homology shared by the X and Y chromosomes. 136\. Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? a. lack of appropriate cell death b. xmetastasis c. changes in order of cell cycle stages d. inability of chromosomes to meet at metaphase plate 137\. Which of the following is ***[not]*** a fundamental law of energy? a. Potential energy cannot be converted to kinetic energy. b. Energy cannot be created or destroyed. c. Energy can be changed from one form to another. d. Energy is lost when it is converted from one form to another. 138\. Identify the ***[incorrect]*** statement: a. ATP consists of an adenine, a sugar, and two phosphate groups. b. When ATP becomes ADP + Pi, the amount of energy released is enough for a biological purpose. c. The structure of ATP allows its breakdown to be easily coupled. d. ATP can be easily recycled. 139\. In the induced fit model of enzyme catalysis, a. the enzyme changes shape slightly to accommodate the substrate. b. the substrate exactly fits multiple enzymes. c. many substrates fit every enzyme. d. the enzyme doesn't fit the substrate until it is induced by another substrate. 140\. Entropy is a term used to indicate the relative amount of a. disorganization. b. organization. c. enzyme action. d. heat. 141\. The active site of an enzyme a. is the part of an enzyme where its substrate can fit. b. is identical in structure for all enzymes. c. can be used only once. d. is not affected by environmental factors, such as pH and temperature. 142\. Why is ATP an important molecule in metabolism? a. It provides energy coupling between exergonic and endergonic reactions. b. Its hydrolysis provides an input of free energy for exergonic reactions. c. Its terminal phosphate group contains a strong covalent bond that when hydrolyzed releases free energy. d. Its terminal phosphate bond has higher energy than the other two. 143\. Which of these statements is correct? a. Energy can be transformed into another type, as shown by the production of ATP in mitochondria. b. Energy can be created, as shown by the production of ATP in mitochondria. c. Energy transformations cannot occur; therefore, ecosystems need a constant input of solar energy. d. Energy lost as heat is recaptured as decreased entropy. 144\. What is an active site? a. the position in an enzyme where substrate bind b. the place where a molecule or ion binds to a protein to induce a shape change c. the portion of a motor protein that is involved in moving cargo in a cell d. the site on an antibody where it binds to bacterial cells or viruses 145\. If a reaction is exergonic, then which of these statements is true? a. The products have lower free energy than the reactants. b. Energy must be added for the reaction to proceed. c. The products have lower entropy (are more ordered) than the reactants. d. The reaction occurs extremely quickly. 146\. What is a transition state? a. the complex formed as covalent bonds are being broken and re-formed during the reaction b. the place where an allosteric regulatory molecule binds to an enzyme c. an interaction between reactants with high kinetic energy, due to high temperature d. the shape adopted by an enzyme that has inhibitory molecule bound at its active site 147\. How does pH affect enzyme-catalyzed reactions? a. the concentration of protons affects the folded structure of the enzyme. b. Protons serve as substrates for most reactions. c. Energy stored in protons is used to drive endergonic reactions. d. Proton concentration increases the kinetic energy of the reactants, allowing them to reach their transition state. 148\. Which of the following statements is representative of the second law of thermodynamics? a. Cells require a constant input of energy to maintain their high level of organization. b. Conservation of energy from one form to another is always accompanied by some gain of free energy. c. Heat represents a form of energy that can be used by most organisms to do work. d. Every energy transformation by a cell decreases the entropy of the universe. 149\. A chemical reaction that has a positive ∆G is correctly described as a. **endergonic** b. endothermic c. spontaneous d. exothermic 150\. Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? a. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive. b. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium. c. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings. d. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment. 151\. When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell? a. **It can be added to other molecules in order to activate them.** b. It is released as an excretory waste. c. It can only be used to generate more ATP. d. It can enter the nucleus to affect gene expression. 152\. Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in a. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. b. the release of water from sucrose as the bond between glucose and fructose is broken. c. production of water from the sugar as bonds are broken between the glucose monomers. d. utilization of water as a covalent bond is formed between glucose and fructose to form sucrase. 153\. A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. Substance A function as \_\_\_ a. an allosteric inhibitor b. a coenzyme c. an intermediate d. a competitive inhibitor 154\. Cellular respiration requires \_\_\_\_(1)\_\_\_\_\_, and \_\_\_\_\_(2) \_\_\_\_\_\_\_ are produced. a. oxygen and glucose, (2) carbon dioxide and water b. water and carbon dioxide, (2) oxygen and water c. oxygen and carbon dioxide, (2) glucose and water d. ATP and glucose, (2) oxygen and water 155\. Where does the acid citric cycle occur in eukaryotes? a. in the matrix of mitochondria b. in the cytosol c. in the inner membrane of mitochondria d. in the intermembrane space of mitochondria 156\. Which of the following would cause cells to switch from cellular respiration to fermentation? a. The final electron acceptor in the electron transport chain is not available. b. The proton-motive force runs down. c. NADH and FADH~2~ supplies are low. d. Pyruvate is not available. 157\. The citric acid cycle results in the release of a. carbon dioxide. b. pyruvate. c. oxygen. d. water. 158\. What is the function of the reactions in a fermentation pathway? a. to generate NAD^+^ from NADH, so glycolysis can continue b. to generate NADH from NAD^+^, so electron can be donated to the electron transport chain c. to synthesize pyruvate from lactate d. to synthesize electron acceptors, so that cellular respiration can continue 159\. The metabolic processes that occur in mitochondria are a. the preparatory reaction, the citric acid cycle, electron transport chain. b. glycolysis, the citric acid cycle, electron transport chain. c. glycolysis, the preparatory reaction, the citric acid cycle. d. glycolysis, the preparatory reaction, electron transport chain. 160\. The metabolic processes that produce carbon dioxide are a. the preparatory reaction, the citric acid cycle. b. glycolysis, the preparatory reaction c. the citric acid cycle, electron transport chain d. glycolysis, the citric acid cycle 161\. The metabolic process that uses ATP is a. glycolysis. b. the preparatory reaction. c. the citric acid cycle. d. electron transport chain. 162\. The metabolic processes that produce NADH are a. glycolysis, the preparatory reaction, the citric acid cycle. b. glycolysis, the preparatory reaction, electron transport chain. c. the preparatory reaction, the citric acid cycle, electron transport chain. d. glycolysis, the citric acid cycle, electron transport chain. 163\. Which of the following is ***[not]*** true of fermentation? a. It donates electrons to the electron transport chain. b. It has a net gain of only 2 ATP. c. It occurs in the cytoplasm. d. It is carried on by humans. 164\. The metabolic process that produces the most ATP molecules is a. the electron transport chain. b. glycolysis. c. the citric acid cycle. d. fermentation. 165\. Fermentation does not yield as much ATP as cellular respiration does because fermentation a. makes use of only a small amount of the potential energy in glucose. b. generates mostly heat. c. creats by-products that require large amounts of ATP to break down. d. creates ATP molecules that leak into the cytoplasm and are broken down. 166\. When animals carry out fermentation, they produce \_\_\_\_(1)\_\_\_\_\_, while yeast produce \_\_\_\_(2)\_\_\_\_\_ a. lactate, (2) ethyl alcohol and CO~2~ b. lactate, (2) NADH c. NADH, (2) ethyl alcohol and CO~2~ d. ethyl alcohol and CO~2~, (2) lactate 167\. The strongest and final electron acceptor in the electron transport chain is a. oxygen. b. NADH. c. FADH~2~. d. water. 168\. If you were to expose cells that are undergoing cellular respiration to a radioactive oxygen isotope in the form of O~2~, which of the following molecules would you expect to be radiolabeled? a. **water** b. pyruvate c. NADH d. CO~2~ 169\. Suppose a drug were added to mitochondria that allowed protons to freely pass through the inner membrane. Which of the following mitochondrial activities would most likely be inhibited? a. oxidative phosphorylation b. the citric acid cycle c. substrate-level phosphorylation d. the electron transport chain 170\. After glucose is fully oxidized by glycolysis, pyruvate processing, and the acid citric cycle, where is the most of the energy stored? a. NADH b. FADH~2~ c. ATP d. NADPH 171\. A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of his condition? a. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. b. His cells cannot move NADH from glycolysis into the mitochondria. c. His cells lack the enzyme in glycolysis that form pyruvate. d. His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA. 172\. When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? a. continue aerobic metabolism when skeletal muscle cannot b. derive sufficient energy from fermentation c. transform lactate to pyruvate again d. remove lactate from the blood 173\. The raw materials for photosynthesis are a. carbon dioxide and water. b. oxygen and water. c. carbohydrate and water. d. carbon dioxide and carbohydrate. 174\. During photosynthesis, carbon dioxide is \_\_\_\_(1)\_\_\_\_\_ and water is \_\_\_\_(2)\_\_\_\_\_\_ a. reduced, (2) oxidized b. oxidized, (2) reduced c. reduced, (2) reduced d. oxidized, (2) oxidized 175\. Photosynthesis occurs best at wavelengths that are a. blue. b. gamma. c. infrared. d. ultraviolet. 176\. What do the light-capturing reactions of photosynthesis produce? a. ATP and NADPH b. G3P c. RuBP d. sucrose or starch 177\. In antenna complexes, how is energy transferred among the pigment molecules? a. resonance b. photophosphorylation c. redox reactions  d. fluorescence 178\. When electrons in the reaction center of PS I are passed to an energy-acceptor molecule, they are replaced by electrons that have been given up by a. water. b. oxygen. c. glucose. d. carbon dioxide. 179\. Which of the following is associated with the thylakoid membrane? a. PS II, ATP production, electron transport chain b. PS I, ATP production, electron transport chain c. PS II, ATP production, Calvin cycle d. PS I, electron transport chain, Calvin cycle 180\. Oxygen is generated by the  a. light reactions. b. Calvin cycle. c. light reactions and the Calvin cycle reactions. d. closing of stomata. 181\. Energy for the Calvin cycle is supplied by \_\_\_\_\_\_\_\_\_ from the light reactions. a. ATP and NADPH b. carbon dioxide and water c. ATP and water d. electrons and hydrogen ions 182\. The product(s) of the Calvin cycle and a reactant(s) in many plant metabolic pathway is/are a. glyceraldehyde 3-phosphate (G3P) b. ribulose-1,5-biphosphate (RuBP) c. adenosine diphosphate (ADP) d. carbon dioxide (CO~2~) 183\. In C4 plants, CO~2~ fixation occurs a. by joining CO~2~ to a C3 molecule and pumping it into bundle sheath cells. b. by adding electrons and a hydrogen ion when splitting water in bundle sheath cells.  c. by splitting water only in bundle sheath cells. d. by oxidizing a C4 molecule with O~2~ derived from bundle sheath cells. 184\. Carbon dioxide fixation occurs when CO~2~ combine with a. RuBP. b. ATP. c. NADPH. d. G3P. 185\. Which of the following statements is ***[not]*** true? a. H^+^ concentration is higher in the stroma than in the thylakoid space. b. The electron transport chain pumps H^+^ from the stroma into the thylakoid space. c. The ATP synthase complex is present in the thylakoid membrane. d. CAM plant - CO~2~ fixation and the Calvin cycle are separated by time. 186\. The enzyme that produces ATP from ADP + P in the thylakoid is a. ATP synthase. b. ATPase. c. RuBP carboxylase. d. coenzyme A. 187\. Each of the following is a product of light reactions ***[except]*** a. sugar. b. ATP. c. NADPH. d. oxygen. 188\. In addition to their protective function, carotenoids absorb certain wavelengths of light and pass the energy to other pigments via resonance. Based on this function, where would you expect carotenoids to be located in the chloroplast? a. the antenna complex b. the reaction centers of photosystem I and II c. the inner membrane of chloroplasts d. the stroma 189\. An investigator exposes chloroplasts to 700-nm photons and observes low O~2~ production, but high ATP production. Which of the following best explains this observation? a. Photosystem II is not splitting water, and the ATP is being produced by cycling electrons via photosystem I. b. The electrons from water are directly transferred to NADP^+^, which is used to generate ATP. c. The O~2~ is being converted to water as a terminal electron acceptor in the production of ATP. d. Electron transport has stopped and ATP is being produced by the Calvin cycle. 190\. P680^+^ is said to be the strongest biological oxidizing agent. Why? a. This molecule results from the transfer of an electron to the primary electron acceptor of photosystem II and strongly attracts another electron. b. It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. c. NADP reductase will then catalyze the shift of the electron from Fd to NADP^+^ to reduce it to NADPH. d. It is the receptor for the most excited electron in either photosystem. 191\. In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (^14^C) dioxide as a metabolic tracer. The ^14^C is incorporated first into oxaloacetate. The plant is the best characterized as a a. C4 plant b. C3 plant c. CAM plant d. chemoautotroph 192\. As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from?  a. **cyclic electron flow** b. photosystem I c. photosystem II d. linear electron flow