Microbiology Test Bank 161 CORRECTLY ANSWERED QUESTIONS LATEST UPDATE

Microbiology - Test Bank 161 CORRECTLY ANSWERED QUESTIONS LATEST UPDATE Which of these is considered to be the smallest unit of life? a) the nucleus b) the mitochondrion c) a plasmid d) the cell e) a prion The study of microbiology includes all of the following EXCEPT _____ . a) plants b) viruses c) bacteria d) fungi e) algae What percent of the dry weight of the cell is composed of DNA? a) 2 - 5 b) 12 -15 c) 25 - 30 d) 35 -40 e) 50 - 55 What are the three Domains of life? a) Monera, Animals, and Plants b) Bacteria, Archaea, and Eukarya c) Prokaryote, Eukaryote, and Fungi d) Animals, Plants, and Bacteria e) Prokaryote, Eukaryote, Archaea Which of the characteristics of life is not displayed by any individual organism? a) metabolism b) growth c) reproduction d) evolution e) response f) homeostasis Viruses are considered "nonliving" for all of the following reasons EXCEPT that they: a) need a host cell for replication. b) are metabolically inert. c) possess DNA that can evolve. d) do not maintain internal homeostasis. e) are not responsive to environmental changes. Which is a macromolecular difference between the Domains Bacteria and Archaea? a) Archaea contain a nucleus and Bacteria do not. b) Bacteria contain DNA and Archaea do not. c) Bacteria contain a plasma membrane and Archaea do not. d) Bacteria cell wall contains peptidoglycan and the Archaea cell wall does not. e) Archaea contain multiple types of RNA polymerase and Bacteria has only one type. The size and shapes of Archaean cells suggest relatedness to: a) Bacteria b) Prokaryotes c) Eukaryotes d) All other life forms e) No other life forms; their sizes and shapes are unique Phosholipid structure in Archaean cells suggests relatedness to: a) Bacteria b) Prokaryotes c) Eukaryotes d) All other life forms e) No other life forms; their structure is unique Which molecular tool most assisted in providing a more reliable way to verify the assertions made by Woese et al in their 1990 paper on phylogeny? a) Polymerase chain reaction b) RNA to DNA conversion using reverse transcriptase c) RNA sequencing d) DNA sequencing e) Protein sequencing If E. coli DNA polymerase, not Taq polymerase were used in polymerase chain reaction assays to amplify SSUrRNA gene sequences, we would expect to see: a) increased short fragment DNA sequences b) decreased short fragment DNA sequences c) the same number of short fragment DNA sequences d) increasd long fragment DNA sequences e) decreased long fragment DNA sequences Figure B1.1 (other side of card) represents an artist's attempt to illustrate the process of PCR. What is the most significant error you notice in this figure? a) DNA strands are not fully denatured b) Primers are not annealed c) PCR products cannot separate from template DNA d) Taq polymerase is not shown in the illustration e) dNTPs are not shown in the illustration Select the answer choice with the correct order in which these structures evolved in plant cells: a) mitochondria, cell walls, chloroplasts b) mitochondria, chloroplasts, cell walls c) chloroplasts, mitochondria, cell walls d) chloroplasts, cell walls, mitochondria e) cell walls, mitochondria, chloroplasts Approximately when did primitive cells first appear on Earth? a) 1 billion years ago b) 2 billion years ago c) 2.5 billion years ago d) 3 billion years ago e) 3.8 billion years ago Which of these are fossilized microbial mats containing photosynthetic bacteria? a) Stromatolites b) Biofilms c) Resin d) Cyanobacteria e) Stalagmites Which statement below is FALSE concerning the atmosphere of early earth? a) The atmosphere was a reducing atmosphere. b) Oxygen was present in very minute amounts. c) Carbon dioxide was present in very minute amounts. d) Hydrogen gas was present. The discovery of ribozymes provides evidence that life on the early Earth may have been based on: a) DNA. b) proteins. c) RNA. d) lipids. e) polysaccharides. What is the Endosymbiotic Theory is used to explain? a) the rapid evolution of viruses b) antiphagocytic abilities of parasitic protozoa c) emergence of cell walls d) presence of mitochondria in eukaryotes e) development of the nucleus in eukaryotes You are a scientific illustrator working on this figure (back of card) Your primary intention when revising this figure is to emphasize the concept of semi-conservative replication. What color changes would you make to the figure to enhance comprehension? a) make all DNA strands blue in the figure b) make the dsDNA a blue-green hybrid and each newly synthesized strand of the color that makes the new dsDNA blue-green hybrid in appearance too c) change all DNA strands to be different colors d) do not make any changes, semi-conservative replication is clearly conceptualized e) all suggestions are equally informative A restriction endonuclease cuts DNA at the sequence ACGT. If we assume that all four bases are equally represented in DNA, what are the odds of this sequence occurring on a DNA strand? a) Roughly every 100 base pairs b) Roughly every 250 base pairs c) Roughly every 1000 base pairs d) Roughly every 10,000 base pairs e) Roughly every 20,000 base pairs In which molecule is the occurrence of mutation most likely to be detected and repaired? a) Single stranded DNA b) Single stranded RNA c) Double stranded DNA d) Protein e) None of these is an information storage molecule The figure shown here (other side of card) relates to the flow of information from DNA to RNA to protein. Select the correct alternative scenario(s) for insertion of leucine instead of phenylalanine during translation. a) Error prone RNA polymerase creates a mutant mRNA from a correct DNA template b) Mutated tRNA introduces leucine instead of phenylalanine against the correct mRNA sequence c) Mutated ribosome creates a environment where mRNA-tRNA mismatches occur infrequently d) Both a and b are possible correct scenarios e) All of these possibilities could explain the translational error Eukaryal life forms without mitochondria do exist. Which of the following do you think they are likely to be? a) animals b) terrestrial plants c) oceanic giant kelps d) single celled protists e) all are equally plausible When would you speculate that the extinction of most eukaryal life forms without mitochondria would have begun? a) 3.5 billion ybp b) 3 billion ybp c) 2 billion ybp d) 1 billion ybp e) 500 million ybp Which of these best describes horizontal gene transfer? a) mitosis followed by cytokinesis b) meiosis and subsequent formation of a zygote c) transfer of genes from mother cell to daughter cell d) DNA replication followed by crossing over e) acquisition of genes from another organism in the same generation Which of these gene expression errors will result in heritable genetic change? a) DNA polymerase error introducing an incorrect base b) RNA polymerase error creating a mutated mRNA c) RNA polymerase error creating a mutated tRNA d) RNA polymerase error creating a mutated rRNA e) All will lead to heritable changes Which is the correct distinction between a heterotroph and an autotroph? a) An autotroph utilizes organic compounds as a carbon source and a heterotroph uses carbon dioxide as a carbon source. b) An autotroph utilizes carbon dioxide as a carbon source and a heterotroph utilizes organic compounds as a carbon source. c) An autotroph utilizes complex organic compounds as a carbon source and a heterotroph utilizes simple organic compounds as a carbon source. d) An autotroph utilizes carbon dioxide as an energy source and a heterotroph utilizes organic compounds as an energy source. e) an autotroph utilizes organic compounds as an energy source and a heterotroph utilizes carbon dioxide as an energy source . Which best describes a photoautotroph? a) Utilizes sunlight for energy and organic molecules as a carbon source. b) Utilizes sunlight as an energy source to fix carbon dioxide. c) Emits light from the breakdown of organic carbon. d) Emits light from the fixation of carbon dioxide. e) Uses organic compounds as a source of carbon and energy. Which best describes the Cyanobacteria? a) First prokaryote to contain mitochondria. b) First appeared on earth about 3.5 billion years ago. c) Carry out oxygenic photosynthesis. d) Members of the Archaea domain. e) A type of eukaryotic algae. A chemoautotroph: a) obtains carbon and energy from organic molecules. b) obtains energy from the sun and carbon from organic molecules. c) obtains energy from the sun and carbon from inorganic molecules. d) obtains carbon and energy from inorganic molecules. e) obtains energy from the sun and carbon from carbon dioxide only.