Exam Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which scientist is credited with coining the term "cell" from the Latin cellulae ? 1) A) Robert Hooke B) Matthias Schleiden C) Antonie van Leeuwenhoek D) Robert Brown E) Theodor Schwann Answer: A Explanation: A) B) C) D) E) 2) Cell biology emerged from which of the following fields of biology? 2) A) genetics B) biochemistry C) cytology D) all of the above E) none of the above Answer: D Explanation: A) B) C) D) E) 3) A scientist is examining motile protozoa. He wishes to determine their direction of movement. Which of the following microscopic techniques is least likely to be used to view these cells? 3) A) phase - contrast microscopy B) fluorescence microscopy C) light microscopy D) electron microscopy E) differential interference contrast microscopy Answer: D Explanation: A) B) C) D) E) 1 4) Which of the following is NOT a tenet of the cell theory? 4) A) The cell is the basic unit of structure for all organisms. B) All cells arise from preexisting cells. C) All organisms consist of one or more cells. D) All cells have a membrane bound nucleus. E) none of the above Answer: D Explanation: A) B) C) D) E) 5) You wish to obtain a pure mitochondria sample from lysed cells. The best way to obtain this sample would be 5) A) polyacrylamide gel electrophoresis. B) chromatography. C) agarose gel electrophoresis. D) centrifugation. E) both A and C. Answer: D Explanation: A) B) C) D) E) 6) In 1665, ________ used a microscope that he had built to examine thin slices of ________. While examining this material, he observed tiny compartments that he called cellulae. 6) A) Robert Brown; plant material B) Robert Hooke; cork C) Antonie van Leeuwenhoek; sperm cells D) Rudolf Virchow; collagen E) Theodor Schwann; animal tissue Answer: B Explanation: A) B) C) D) E) 2 7) The steps of the "scientific method," in the correct order, are 7) A) collect data, interpret results, test the hypothesis, make observations, and design experiments. B) collect data, interpret results, test the hypothesis, design experiments, make observations, and draw conclusions. C) design experiments, draw conclusions, collect data, interpret results, make observations, and test the hypothesis. D) make observations, formulate the hypothesis, design experiments, collect data, interpret results, and draw conclusions. E) none of the above Answer: D Explanation: A) B) C) D) E) 8) A microtome is used to 8) A) dissect cellular organelles. B) slice thin sections of specimens. C) focus short wavelengths of light. D) view microscopic organisms. E) manipulate tiny objects. Answer: B Explanation: A) B) C) D) E) 9) Which of the following is NOT true of brightfield microscopy? 9) A) White light is utilized. B) Specimens usually must be fixed. C) Phase - contrast microscopy is a variant of brightfield microscopy. D) Specimens are always viewed without being stained. E) Light passes through the object being examined. Answer: D Explanation: A) B) C) D) E) 3 10) Gregor Mendel was most influential in which field of biology? 10) A) chromatography B) cytology C) genetics D) bacterial transformation E) biochemistry Answer: C Explanation: A) B) C) D) E) 11) Of the following specialized procedures, which may be used with the electron microscope? 11) A) scanning electron microscopy B) freeze fracturing C) shadowing with gold D) negative staining E) all of the above Answer: E Explanation: A) B) C) D) E) 12) Which of the following is closest to a micrometer in size? 12) A) the width of a strand of DNA B) a typical bacterial cell C) the length of a plant cell D) the size of a ribosome E) the length of a chicken egg Answer: B Explanation: A) B) C) D) E) 13) The classic work of Wöhler (1828) that united the fields of biology and chemistry was based on the 13) A) identification of nucleotide bases. B) production of urea in the laboratory. C) discovery of ATP. D) discovery of yeast ferments. E) analysis of gene segregation. Answer: B Explanation: A) B) C) D) E) 4 14) All of the following biochemical techniques have allowed us to understand cell structure and function EXCEPT 14) A) ultracentrifugation. B) mass spectrometry. C) electrophoresis. D) light microscopy. E) chromatography. Answer: D Explanation: A) B) C) D) E) 15) Which of the following can ONLY be viewed by electron microscopy? 15) A) frog eggs B) bacteria C) viruses D) mitochondria E) nuclei Answer: C Explanation: A) B) C) D) E) 16) Which laws were formulated by Mendel? 16) A) heredity B) diffusion C) thermodynamics D) ideal gas laws E) gravity Answer: A Explanation: A) B) C) D) E) 5 17) The outcome of the joining of cytology and biochemistry yielded a better understanding of the cell by 17) A) identification of cellular biochemical pathways. B) identification of cellular structures. C) demonstration of bioinformatics. D) both A and B. E) both B and C. Answer: D Explanation: A) B) C) D) E) 18) Which type of microscopy enhances and amplifies slight changes in the phase of transmitted light? 18) A) differential interference contrast microscopy B) fluorescence microscopy C) digital video microscopy D) phase - contrast microscopy E) both A and D Answer: E Explanation: A) B) C) D) E) 19) Once a scientific theory becomes a law, it 19) A) cannot be changed. B) becomes static. C) is subject to modification. D) is irrefutable. E) cannot be challenged. Answer: C Explanation: A) B) C) D) E) 6 20) Melvin Calvin and his colleagues used which of the following to deduce the steps in the Calvin Cycle? 20) A) Drosophila melanogaster B) radioisotopes C) negative staining D) ultracentrifugation E) electron microscopy Answer: B Explanation: A) B) C) D) E) 21) Jacques Monod and François Jacob deduced the mechanism responsible for the regulation of bacterial gene expression. They are, therefore, responsible for launching the era of 21) A) biochemistry. B) light microscopy. C) radioisotopes. D) the scientific method. E) molecular genetics. Answer: E Explanation: A) B) C) D) E) 22) Scanning electron microscopy (SEM) is especially suited to 22) A) creating a sense of depth. B) observe living specimens. C) examine internal cellular structure. D) both A and C. E) choices A, B, and C. Answer: A Explanation: A) B) C) D) E) 7 23) Which organelle is round and derives its name from the Latin word for "kernel"? 23) A) mitochondrion B) nucleus C) Golgi complex D) chloroplast E) lysosome Answer: B Explanation: A) B) C) D) E) 24) When scientists use the scientific method, they use terms to indicate their degree of certainty. Which of the following terms conveys the least degree of certainty? 24) A) theory B) law C) hypothesis D) both hypothesis and theory E) both theory and law Answer: C Explanation: A) B) C) D) E) 25) Which of the following is smallest? 25) A) a mitochondrion B) a bacterium C) a virus D) a ribosome E) a protein Answer: E Explanation: A) B) C) D) E) 26) Which of the following is true of a nanometer? 26) A) A nanometer is one millionth of a meter. B) A nanometer is about the size of a common bacterial cell. C) The nanometer is the most common measurement used in measuring whole cells. D) A nanometer is equivalent to 10 Angstoms (Å). E) none of the above Answer: D Explanation: A) B) C) D) E) 8 27) The Latin phrase omnis cellula e cellula refers to a cellular principle. Which of the following statements is the best translation of this phrase? 27) A) Tissues are composed of similar cells. B) The cell is the basic unit of structure. C) Organs are composed of tissues and cells. D) All cells arise only from preexisting cells. E) Cells generally are found in clusters. Answer: D Explanation: A) B) C) D) E) 28) Which of the following is true of fluorescence microscopy? 28) A) Fluorescence microscopy is best at viewing rounded, thicker specimens. B) Fluorescent light is emitted throughout the specimen being viewed. C) Fluorescence microscopy is able to overcome problems with confocal scanning microscopy. D) Fluorescence microscopy presents images in three dimensions. E) Fluorescence microscopy is used to view dead specimens only. Answer: B Explanation: A) B) C) D) E) 29) The limit of resolution can best be defined as 29) A) the magnification power of a microscope. B) the distance that an object must be moved to be distinguished from its background. C) the solvent that must be available to remix a solution. D) the distance that two objects must be apart to be distinguished as separate objects. E) the inverse of the wavelength of light; it is greatest for black light. Answer: D Explanation: A) B) C) D) E) 9 30) The scientific work that established DNA, rather than protein, as the molecule of heredity is credited to 30) A) Monod and Jacob. B) Watson and Crick. C) Correns, von Tschermak, and de Vries. D) Avery, MacLeod, and McCarty. E) Beadle and Tatum. Answer: D Explanation: A) B) C) D) E) 31) Which type of microscopy has the greatest resolving power? 31) A) phase - contrast B) digital video C) electron D) fluorescence E) confocal scanning Answer: C Explanation: A) B) C) D) E) 32) 1 mm = ________ nm 32) A) 1/1000 B) 10 C) 1/1,000,000 D) 1,000,000 E) 1000 Answer: D Explanation: A) B) C) D) E) SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 33) To be useful to scientists, a hypothesis must be ________. In other words, the hypothesis must be able to be confirmed or discredited. 33) Answer: testable Explanation: 34) A(n) ________ is an instrument used to separate subcellular structures and macromolecules on the basis of size, shape, and density. ________ developed this instrument in Sweden during the period 1925 - 1930. 34) Answer: ultracentrifuge; Theodor Svedberg Explanation: 10 35) Because of the low penetration power of electrons, samples for transmission electron microscopy must be extremely thin. A(n) ________ is able to cut sections as thin as 20 nm. 35) Answer: ultramicrotome Explanation: 36) In 1880, Walther Flemming identified ________, threadlike bodies seen in dividing cells. 36) Answer: chromosomes Explanation: 37) ________ synthesized urea in the laboratory from inorganic starting materials. Much of what is now called ________ dates from this discovery. 37) Answer: ¨ Friedrich W o hler; biochemistry Explanation: 38) Around 1914, ________ determined that DNA was an important component in ________ by using a staining technique that is still in use today. 38) Answer: Robert Feulgen; chromosomes Explanation: 39) Glycolysis is also called the ________ pathway after the scientists who did most of the work to define it. 39) Answer: Embden - Meyerhof Explanation: 40) The total protein content of the cell is called the ________. 40) Answer: proteome Explanation: 41) The ________ was developed in the late 1920s by Theodore Svedberg. He originally used it to determine the sedimentation rate of proteins. 41) Answer: ultracentrifuge Explanation: 42) ________ is the ability to distinguish two objects that are close together as separate. When using a light microscope, this ability is determined by ________. 42) Answer: Resolution; lambda or wavelength Explanation: 43) A scientific ________ must be so thoroughly confirmed that virtually no doubt remains about its accuracy. 43) Answer: law Explanation: 44) Melvin Calvin used ________, a specific ________, to deduce the Calvin cycle of photosynthesis. 44) Answer: 14 - C; radioisotope Explanation: 11 45) ________ is a biochemical technique that allows one to separate biological molecules based on size, shape, and/or affinity for specific molecules or functional groups. 45) Answer: Chromatography Explanation: MATCHING. Choose the item in column 2 that best matches each item in column 1. Match each scientist or group of scientists on the left with the appropriate statement to the right. 46) Friedrich Wöhler Answer: B A) oral bacteria B) urea 46) Match the type of microscopy with the appropriate characteristic. 47) Fluorescence Answer: A A) shows specific molecules 47) Match each scientist or group of scientists on the left with the appropriate statement to the right. 48) George Beadle and Edward Tatum Answer: B A) transcription B) "one gene - one enzyme" 48) Match the type of microscopy with the appropriate characteristic. 49) Brightfield Answer: A A) light passes directly through specimen 49) Match each scientist or group of scientists on the left with the appropriate statement to the right. 50) Gregor Mendel Answer: D 51) Thomas Hunt Morgan Answer: A A) fruit fly B) Calvin cycle C) dog saliva D) hereditary factors 50) 51) Match the type of microscopy with the appropriate characteristic. 52) Phase - contrast Answer: A A) amplifies variations in density 52) Match each scientist or group of scientists on the left with the appropriate statement to the right. 53) Louis Pasteur Answer: A A) "ferments" of yeast 53) 12 Match the type of microscopy with the appropriate characteristic. 54) Transmission electron microscopy Answer: A A) detects electrons passing through a specimen 54) Match each scientist or group of scientists on the left with the appropriate statement to the right. 55) Matthias Schleiden Answer: A A) embryonic plant B) embryonic bacteria 55) Match the type of microscopy with the appropriate characteristic. 56) Scanning electron microscopy Answer: A A) detects electrons deflected from the surface of the specimen 56) Match each scientist or group of scientists on the left with the appropriate statement to the right. 57) Oswald Avery, Colin MacLeod, and Maclyn McCarty Answer: A 58) James Watson and Francis Crick Answer: D A) transformation B) transfer RNA C) translation D) DNA double helix 57) 58) Match the type of microscopy with the appropriate characteristic. 59) Confocal Answer: A A) uses a laser to view a single plane of a specimen 59) Match each scientist or group of scientists on the left with the appropriate statement to the right. 60) Walter Sutton Answer: A A) chromosome theory of heredity B) pollen grain 60) 13 ESSAY. Write your answer in the space provided or on a separate sheet of paper. 61) Scientific discoveries have had great impact in human history. The people who make these discoveries and the circumstances that surround these discoveries are very important to our understanding of science. Can you identify the individuals as they might have described themselves? a. I am a seventeenth century shopkeeper from Holland. My hobby involves hand - polishing glass to make lenses, some of which can magnify almost 300 - fold. I was the first to observe living cells and am known as the "Father of Microbiology." b. I was the Curator of Instruments for the Royal Society of London in 1665. I developed a crude microscope that could magnify around 30 - fold. I examined plant material and observed many small chambers that I called cellulae . c. At the University of California, Berkeley, I worked with radioisotopes. In the late 1940s and early 1950s, I used carbon - 14 to identify the most common pathway for photosynthetic carbon metabolism. d. We worked out the double helix model of DNA structure in 1953. We later received the Nobel Prize for this work. e. I am a nineteenth century German chemist. By synthesizing an organic molecule from inorganic components, I dispelled the idea that biological processes were exempt from the laws of chemistry. f. My colleague and I worked with bacterial viruses. We were able to demonstrate that DNA and not protein was the genetic material of the cell. g. I am a Swedish scientist. I developed the ultracentrifuge to determine sedimentation rates of proteins. The ultracentrifuge was later used to isolate subcellular fractions. Answer: a. Antonie van Leeuwenhoek b. Robert Hooke c. Melvin Calvin d. James Watson and Francis Crick e. Friedrich Wohler f. Alfred Hershey and Martha Chase g. Theodor Svedberg 62) A number of different types of microscopy exist. Each type of microscopy has advantages and disadvantages. Can you identify the microscope that would be most advantageous for the situation below? a. A cell biologist wishes to visualize the ribosomes of a cell. b. A bacteriologist wishes to examine the motility of a bacterium. c. An immunologist wishes to determine if a lymphocyte possesses a certain surface protein. d. A virologist is trying to determine the three - dimensional shape of a virus. e. A pathologist is trying to examine the cytoplasm of a cell for changes that result from viral infection. Answer: (Answers may vary.) a. Electron microscopy, preferably transmission electron microscopy, should be used. b. Phase contrast or differential - interference - contrast would be most helpful. c. Fluorescence microscopy is often used. d. Scanning electron microscopy should be used. e. Transmission electron microscopy will enable the pathologist to visualize the interior. 14 63) The following paragraph describes the activities of hypothetical scientists. After reading this paragraph, list the steps to the scientific method and list the activities that correspond to the steps of the scientific method. A rancher noticed that several grazing animals had become sick after grazing in a new area. The rancher asked a team of scientists to analyze this problem. They visited the area and found that the food available to the animals was similar to the food they had been eating. The water supply in the area was adequate but was limited to a single spring. Some of the scientists felt that the water might be contaminated with a pathogen. Therefore, they collected water samples from the spring in the new area and compared them with water samples taken from previous grazing sites. The scientists noticed that water from the new area was cloudier than water obtained from other areas. Culturing this water revealed that a pathogenic strain of bacteria was present. This bacterial strain was found to be identical to a strain obtained from sick animals. This strain was not present in healthy animals. They concluded that a contaminated water supply in the new area was responsible for the problem and instructed the rancher to avoid the water supply. The disease was not found in the rancher's livestock again. Answer: (Please note that answers may vary.) Observation. The rancher and the scientists made initial observations regarding the food and water that the livestock consumed. Hypothesis. The water supply was contaminated with a pathogen. Experimentation. Water was collected, examined, and cultured. Collect data. The turbidity of the water was examined. The cultures were positive for a pathogenic strain of bacterium. Interpret results. The data was compared to other water samples. The cultures were compared to those obtained from livestock. Draw conclusion. The water was contaminated and responsible for the outbreak. 15