Bio exam 1 – Flashcards
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Which of the following characteristics is typical of the lytic cycle of a bacteriophage?
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A large number of phages are released at a time.
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Which of the following characteristics correctly describes retroviruses?
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They have a single-stranded RNA that acts as a template for DNA synthesis.
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What is the function of reverse transcriptase in retroviruses?
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It uses viral RNA as a template for DNA synthesis.
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Some viruses can be crystallized and their structures analyzed. One such virus is yellow mottle virus, which infects beans. This virus has a single-stranded RNA genome containing about 6,300 nucleotides. Its capsid is 25-30 nm in diameter and contains 180 identical capsomeres. If the yellow mottle virus begins its infection of a cell by using its genome as mRNA, which of the following would you expect to be able to measure when analyzing the reproduction of this virus?
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translation rate
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Which of the following is the smallest structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope?
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mitochondrion
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A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based just on this information, the organism is most likely ________.
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a motile eukaryote
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Which of the following is a major difference between prokaryotic cells and eukaryotic cells?
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Prokaryotic cells have cell walls, while eukaryotic cells do not.
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Which domains of life are classified as prokaryotes?
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Bacteria and Archaea
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Which structure is common to plant and animal cells?
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mitochondrion
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Which of the following are found in plant, animal, and bacterial cells?
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ribosomes
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In bacteria, DNA will be found in
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the nucleoid
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What is the function of the nuclear pore complex found in eukaryotes?
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It regulates the movement of proteins and RNAs into and out of the nucleus.
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Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane?
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mRNA
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Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane?
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ribosomal proteins
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Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
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Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
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Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules?
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proteins
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. A cell with a predominance of rough endoplasmic reticulum is most likely ________.
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producing large quantities of proteins for secretion
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Which organelle often takes up much of the volume of a plant cell?
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central vacuole
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A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________.
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synthesize large quantities of lipids
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Which structure below is independent of the endomembrane system?
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chloroplast
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Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition?
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the lysosome
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. The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?
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smooth endoplasmic reticulum
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. Which of the following organelles produces and modifies polysaccharides that will be secreted?
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Golgi apparatus
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Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell?
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rough ER → Golgi → transport vesicle → plasma membran
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Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. As a result, asbestos fibers accumulate in ________.
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lysosomes
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Which organelle is the primary site of ATP synthesis in eukaryotic cells?
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mitochondrion
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Cilia and flagella bend because of ________.
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a motor protein called dynein
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Which of the following methods would be most successful in attempting to introduce a particular piece of DNA into an animal cell?
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electroporation followed by recombination
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Which of the following processes helps bacterial cells protect their own DNA from restriction enzymes (endonucleases)?
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adding methyl groups to adenines and cytosines
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A principal problem with inserting an unmodified mammalian gene into a plasmid and then getting that gene expressed in bacteria is that ________.
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bacteria cannot remove eukaryotic introns
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Why are yeast cells frequently used as hosts for cloning?
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They are eukaryotic cells.
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. Why is sequencing an entire genome, such as that of C. elegans, a nematode, important for genetic research?
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A sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates.
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Which of the following methods would be most successful in attempting to introduce a particular piece of DNA into an animal cell?
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electroporation followed by recombination
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For which of the following processes can dideoxyribonucleotides be used?
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to sequence a DNA fragment
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Many identical copies of genes cloned in bacteria are produced as a result of which of the following processes?
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plasmid and bacterial cell reproduction
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What information is critical to the success of polymerase chain reaction (PCR) itself?
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The DNA sequence of the ends of the DNA to be amplified must be known.
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Which of the following correctly lists the processes in order for one cycle of polymerase chain reaction (PCR)?
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denature DNA; anneal primers; extend primers
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How can a gene that contains introns be made shorter (but remain functional) for genetic engineering purposes?
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using reverse transcriptase to reconstruct the gene from its mRNA
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Which of the following enzymes is required to make complementary DNA (cDNA) from RNA?
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reverse transcriptase
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Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells?
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Embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot.
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Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following safety measures is one that has been adopted by researchers?
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Microorganisms used in recombinant DNA experiments must be genetically crippled to ensure that they cannot survive outside of the laboratory.
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What is the most favorable characteristic of retroviruses that makes them useful in gene therapy applications?
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DNA copies of retroviral genomes become integrated into the genome of the infected cell
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. Which of the following tools of DNA technology is incorrectly paired with its use?
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DNA ligase—cutting DNA, creating sticky ends of restriction fragments
