AP Biology Cells: Chapters 4 & 5

Transcription

1 AP Biology Cells: Chapters 4 & 5 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The was the first unifying principle of biology. a. spontaneous generation theory b. cell theory c. germ theory of disease d. theory of genetic determinism e. law of Ohno 2. DNA strands can be visualized using which of the following instruments? a. Light microscope b. Electron microscope c. Dissecting microscope d. Centrifuge e. Thermocycler 3. The organelles and biomolecules present in homogenized cells can be separated by centrifugation. Which of the following would be found at the top of a centrifugation gradient? a. golgi b. mitochondria c. nuclei d. ribosomes e. ATP molecules 4. Prokaryotesa. are surrounded by a plasma membrane. a. have a nucleus. b. do not have ribosomes. c. have a cell wall similar in composition to that of plant cells. d. are larger than eukaryotic cells. 5. The proteins that make up the cytoskeleton of bacteria are similar to in eukaryotic cells. a. proteases b. sterols c. actin d. transcription factors e. telomerases 6. Nucleic acids are not found in which of the following structures? a. The nucleus b. Mitochondria c. Plant vacuoles d. Ribosomes e. Prokaryotic cells 7. Some proteins that are on the surface of mammalian cells contain carbohydrates. These proteins are synthesized by and the sugars added in the. a. mitochondrial ribosomes; smooth endoplasmic reticulum b. the rough endoplasmic reticulum; Golgi apparatus c. cytoplasmic ribosomes; smooth endoplasmic reticulum

2 d. Golgi apparatus; rough endoplasmic reticulum e. cytoplasmic ribosomes; plasma membrane 8. Which of the following statements about the nucleus in animal cells is false? a. The nucleus occupies the largest volume of the cell. b. DNA replication takes place in the nucleus. c. The nucleolus is located in the nucleus. d. DNA in the nucleus combines with proteins. e. The nucleus is the site of protein synthesis. 9. The endomembrane system a. is present in prokaryotes. b. includes the endoplasmic reticulum and the mitochondria. c. includes the Golgi apparatus and the endoplasmic reticulum. d. functions to make ATP. e. does not exist in plant cells. 10. Which of the following organelles is involved in energy conversions? a. Lysosomes b. Vacuoles c. Chloroplasts d. Peroxisomes e. Nuclei 11. Liver cells are exposed to radioactive amino acids; all proteins synthesized during this time are radioactive. The cells are then removed at 5-minute intervals and fractionated. Where in the cells is the radioactively labeled enzyme lipase performing its intracellular functions? a. In the endoplasmic reticulum b. In the Golgi c. In lysosomes d. On ribosomes e. In the cytoskeleton 12. Which of the following organelles are found only in plants? a. Glyoxysomes b. Golgi c. Peroxisomes d. Mitochondria e. Endoplasmic reticulum 13. Which of the following structures occupies the largest volume in a mature plant cell? a. Peroxisome b. Ribosome c. Chloroplast d. Vacuole e. Mitochondrion 14. Plastids are a. present in nearly all plant cells. b. always green. c. present in photosynthetic prokaryotes. d. present in all eukaryotes. e. very similar to mitochondria.

3 15. Which of the following structures is directly involved with the movement of organelles within a cell? a. Golgi apparatus b. Endoplasmic reticulum c. Mitochondrion d. Microtubules e. Intermediate filaments 16. Which of the following proteins powers the movement of both cilia and vesicles within a cell? a. Myosin b. Actin c. Keratin d. Dynein e. Kinesin 17. Cilia and eukaryotic flagella a. propel cells by rotation of the structures. b. contain microfilaments. c. contain microtubules that are sufficient to drive movement. d. must have a motor protein that uses the energy of ATP hydrolysis to power movement. e. contain centrioles. 18. Amoeba proteus is injected with a drug that inhibits the formation of microtubules. What effect does this have on the organism s movement? a. It is alive but rounds up and does not move. b. It shows hyperactive movement. c. It dies. d. It only moves in one direction. e. It continues to move with no effect. 19. The extracellular matrix of animal cells a. is involved in chemical signaling between cells. b. helps filter materials passing between tissues. c. contains proteoglycans. d. contains collagen. e. All of the above 20. The presence of means that substances must pass through, rather than between, the epithelial cells that form the lining of the small intestine. a. gap junctions b. tight junctions c. desmosomes d. plasmodesmata e. Both a and b 21. Phospholipids spontaneously form bilayer structures, but oils form small droplets. Why do oils not form bilayers? a. Oils are not as hydrophobic as phospholipids. b. The fatty acids in oils preclude bilayer formation. c. Oils are energy reserves of cells. d. Oils do not have the polar head group that phospholipids have. e. Oils and water do not mix.

4 22. Which of the following statements about membrane proteins is false? a. Hydrophilic regions of integral membrane proteins are in contact with the interior of the bilayer. b. Peripheral membrane proteins may be associated with the phospholipid head groups. c. Integral membrane proteins can move in the plane of the membrane. d. Some membrane proteins may have oligosaccharides attached to them. e. None of the above 23. In addition to the bilayer lipids and proteins, membranes may contain in the form of and. a. nucleic acids; DNA; RNA b. carbohydrates; cellulose; starch c. triglycerides; fats; oils d. nucleotides; ATP; GTP e. carbohydrates; glycoproteins; glycolipids 24. In animals, cell recognition a. involves only glycolipids. b. is mediated by the lipid bilayer. c. involves soluble proteins. d. involves proteins in plasma membranes. e. is usually heterotypic. 25. Which of the following molecules do you think would diffuse across a phospholipid bilayer fastest, assuming that there are no proteins associated with the bilayer? [Hint: Keep in mind the nature of the interior of the bilayer.] a. H 2O b. NH 4 + c. CH 3COO d. Na + e. NH Osmosis is a. the movement of water across membranes. b. the active transport of water across membranes. c. unidirectional diffusion of water across membranes. d. unaffected by solute concentrations inside cells. e. a process that requires energy. 27. What would happen if a suspension of red blood cells in an isotonic NaCl solution was suddenly diluted with pure water by a factor of 10? a. Nothing would happen. b. The cells would lose water and shrink. c. The cells would swell and lyse (burst). d. The cells would take up water, but the cell wall would prevent bursting. e. The cells would pump water out of the cell. 28. In facilitated diffusion, a. molecules may be transported against their concentration gradient. b. specific integral membrane proteins mediate transport. c. the rate of transport is independent of the concentration of the molecule transported. d. ATP is used.

5 e. endocytosis is involved. 29. The sodium potassium pump (or Na + K + pump) a. is present in endomembranes. b. is an example of a secondary active transporter. c. results in the formation of Na + concentration gradient across the plasma membrane. d. carries out facilitated diffusion. e. pumps K + out of cells. 30. Receptor-mediated endocytosis a. is non-specific. b. allows small molecules to enter cells. c. results in the formation of clathrin-coated vesicles. d. directly involves the Golgi apparatus. e. is another name for phagocytosis. 31. Hormones are chemical signals that a. affect adjacent cells. b. work in prokaryotes. c. are autocrine signals. d. travel through circulatory systems. e. are paracrine signals. 32. A universal feature of receptors is that they a. undergo structural (shape) changes when the signal molecule is bound. b. are protein kinases. c. are present in the plasma membrane. d. are ion channel proteins. e. do not undergo structural (shape) changes when the signal molecule is bound. 33. Which of the following statements about receptors and enzymes is true? a. Most receptors and enzymes are nucleic acids. b. Both receptors and enzymes may be integral membrane proteins. c. Receptor ligands, like enzyme substrates, are altered during signal transduction. d. Both receptors and enzymes are not specific for the molecules they bind. e. Receptors generally have enzymatic activity, whereas enzymes do not. 34. Chemical signal transduction pathways a. use non-specific receptors. b. involve binding of the signal molecule to receptors. c. use receptors that are located only on the plasma membrane. d. use receptors that change the ligands they bind. e. all use G proteins. 35. Adenylyl cyclase a. is located such that camp is made outside of cells. b. makes camp from ATP with the liberation of phosphate (P i). c. is inactivated by activated G proteins. d. makes camp from ATP with the liberation of pyrophosphate (PP i). e. is directly activated by receptors. 36. Which of the following statements is true? a. Glycogen phosphorylase in liver cells is always active.

6 b. camp is referred to as a first messenger. c. Epinephrine directly activates adenylyl cyclase. d. camp is referred to as a second messenger. e. Adenylyl cyclase is a protein kinase. 37. Which step of the signal transduction cascade that results in glucose release during the fight-or-flight response does not directly involve a nucleotide? a. Phosphorylation of glycogen phosphorylase b. Activation of adenylyl cyclase c. Epinephrine binding to its receptor d. Activation of a G protein e. Inactivation of glycogen synthase 38. The phosphorylation of proteins by ATP a. is catalyzed by enzymes known as protein kinases. b. always stimulates the activity of an enzyme. c. is catalyzed by adenylyl cyclase. d. is catalyzed by the epinephrine receptor. e. is catalyzed by G proteins. 39. Suppose the concentration of epinephrine in the blood stream of an animal drops. The cyclic AMP concentration in liver cells would be expected to because activity would. a. increase; adenylyl cyclase; increase b. decrease; protein kinase; decrease c. decrease; phoshodiesterase; decrease d. increase; protein kinase; increase e. decrease; adenylyl cyclase; decrease 40. Caffeine a. is structurally related to GDP. b. binds to a receptor in the brain. c. causes signal transduction by itself. d. is a signal. e. is a depressant.