Midterm 2 Chee 370

35 Questions | Total Attempts: 230

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Midterm Biology Quizzes & Trivia

Questions and Answers
  • 1. 
    What term would be applied to a regulatory condition that occurs when protein is associated with a particular section of DNA and greatly reduces transcription?
    • A. 

      Induction

    • B. 

      Activation

    • C. 

      Negative control

    • D. 

      Positive control

    • E. 

      Stimulation

  • 2. 
    Secondary metabolites appear during which of the following stages?
    • A. 

      At, near, or in the lag phase

    • B. 

      At, near, or in the stationary phase

    • C. 

      At, near, or in the exponential phase

    • D. 

      At, near, or in the death phase

  • 3. 
    DNA moves within an electric field because it
    • A. 

      Is positively charged

    • B. 

      Is negatively charged

    • C. 

      Makes up chromosomes, which are slightly electromagnetic

    • D. 

      Can possess different charges (positive or negative) depending on its base sequence

  • 4. 
    Which of the following is NOT a means of regulating gene expression?
    • A. 

      Modifying proteins after they are synthesized

    • B. 

      Varying the rate at which messenger RNAs are transcribed

    • C. 

      Varying the rate at which messenger RNAs are translated

    • D. 

      Deleting genes from cells in which they are not needed

    • E. 

      Regulating the life span of a protein

  • 5. 
    Dideoxyribonucleotides (ddNTPs) used for DNA sequencing lack oxygen atoms at
    • A. 

      The 1' carbon of the pentose sugar

    • B. 

      The 3' and 5' carbons of the pentose sugar

    • C. 

      The 2' and 3' carbons of the pentose sugar

    • D. 

      The 1' and 2' carbons of the pentose sugar

    • E. 

      The 5' carbon of the pentose sugar

  • 6. 
    Which of the following best describes siRNA?
    • A. 

      A double-stranded RNA that is formed by cleavage of hairpin loops in a larger precursor

    • B. 

      A molecule, known as Dicer, that can degrade other mRNA sequences

    • C. 

      A portion of rRNA that allows it to bind to several ribosomal proteins in forming large or small subunits

    • D. 

      A short double-stranded RNA, one of whose strands can complement and inactivate a sequence of mRNA

    • E. 

      A single-stranded RNA that can, where it has internal complementary base pairs, fold into cloverleaf patterns

  • 7. 
    The reason for using Taq polymerase for PCR is that
    • A. 

      Only minute amounts are needed for each cycle of PCR

    • B. 

      It has regions that are complementary to primers

    • C. 

      It is heat stable and can withstand the temperature changes of the cycler

    • D. 

      It binds more readily than other polymerases to primer

    • E. 

      All of these are correct

  • 8. 
    Yeast artificial chromosomes contain which of the following elements?
    • A. 

      Origin of replication only

    • B. 

      Centromeres and telomeres only

    • C. 

      Centromeres, telomeres, and an origin of replication

    • D. 

      Telomeres only

  • 9. 
    Some vectors such as pUC18 and others of the pUC series contain a large number of restriction enzyme sites clustered in one region. What term is given to this advantageous arrangement of restriction sites?
    • A. 

      Palindrome

    • B. 

      Complementation

    • C. 

      Consensus sequence

    • D. 

      Polylinker

    • E. 

      B-galatosidase

  • 10. 
    A metabolite excreted by a microorganism during exponential growth is called 
    • A. 

      Primary metabolite

    • B. 

      Immobilized enzyme

    • C. 

      Secondary metabolite

    • D. 

      Exoenzyme

  • 11. 
    Which pair of enzymes is necessary to make recombinant DNA?
    • A. 

      Ligase and restriction enzyme

    • B. 

      DNA polymerase and RNA polymerase

    • C. 

      DNA polymerase and ligase

    • D. 

      Restriction enzyme and DNA polymerase

  • 12. 
    Type II restriction endonucleases
    • A. 

      Natively function to methylate specific nucleotides and prevent foreign DNA from being incorporated into the genome

    • B. 

      Recognize nucleotide sequences that are palindromic

    • C. 

      Are heterodimers

    • D. 

      Require ATP energy to cleave dsDNA

  • 13. 
    The promoters of positively controlled operons require activator proteins, because
    • A. 

      RNA polymerase easily recognizes the consensus sequence

    • B. 

      They are needed to bind to the allosteric site of RNA polymerase

    • C. 

      They are required to inactivate the repressor proteins

    • D. 

      The promoters have nucleotide sequences that bind RNA polymerase weakly, which are not close matches to the consensus sequence

  • 14. 
    Suppose ENZ-1 and ENZ-2 are two different restriction enzymes. If various pieces of DNA from different species are cut with these enzymes (as follows), which would most easily form recombinant molecules?
    • A. 

      Human DNA cut with ENZ-1 and gorilla DNA cut with ENZ-2

    • B. 

      Human DNA cut with ENZ-1 and human DNA cut with ENZ-2

    • C. 

      Bacterial DNA cut with ENZ-1 and gorilla DNA cut with ENZ-2

    • D. 

      Human DNA cut with ENZ-2 and bacterial DNA cut with ENZ-2

  • 15. 
    In biotechnology research, DNA fragments created by restriction enzyme action are separated from one another via
    • A. 

      Centrifugation

    • B. 

      Crossing over

    • C. 

      The polymerase chain reaction

    • D. 

      Gel electrophoresis

    • E. 

      Filtering

  • 16. 
    Genomic imprinting, DNA methylation, and histone acetylation are all examples of
    • A. 

      Karyotypes

    • B. 

      Chromosomal rearrangements

    • C. 

      Epigenetic phenomena

    • D. 

      Genetic mutation

    • E. 

      Translocation

  • 17. 
    Which of the following is the correct sequence of the polymerase chain reaction?
    • A. 

      Heat to 90 celsius (to bind primers and enzymes), then cool to 50 celsius (to separate DNA), then reheat to 70 celsius (to synthesize DNA)

    • B. 

      Heat to 70 celsius (to bind primers and enzymes), then cool to 50 celsius (to synthesize DNA), then reheat to 90 celsius (to separate DNA)

    • C. 

      Heat to 90 celsius (to separate DNA), then cool to 50 celsius (to bind primers and enzymes), then reheat to 70 celsius (to synthesize DNA)

    • D. 

      Heat to 70 celsius (to separate DNA), then cool to 50 celsius (to bind primers and enzymes), then reheat to 90 celsius (to synthesize DNA)

  • 18. 
    A ______ consists of cloned DNA fragments for all expressed genes in a particular tissue. 
    • A. 

      PCR library

    • B. 

      Shotgun library

    • C. 

      Guggenheim library

    • D. 

      Genomic DNA library

    • E. 

      CDNA library

  • 19. 
    A _______ is a single-stranded DNA molecule attached to a radioactive or fluorescent compound that is complementary to a specific sequence of DNA. Such pieces of DNA are used to identify and study cloned genes in hybridization experiments. 
    • A. 

      Probe

    • B. 

      Vector

    • C. 

      Promoter

    • D. 

      Polypeptide

    • E. 

      Plasmid

  • 20. 
    Which of the following does not apply to eukaryotic gene regulation?
    • A. 

      Regulation as a result of compartmentalization

    • B. 

      Protein degradation (turnover)

    • C. 

      Gene regulation by attenuation

    • D. 

      Protein folding

    • E. 

      MRNA degradation (turnover)

  • 21. 
    A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate?
    • A. 

      A large polypeptide

    • B. 

      A plant virus

    • C. 

      A plasmid

    • D. 

      A typical bacteriophage

    • E. 

      A BAC

  • 22. 
    When making a complementary DNA (cDNA) library, which enzyme is used to copy mRNA into DNA?
    • A. 

      RNA polymerase

    • B. 

      Primase

    • C. 

      Reverse transcriptase

    • D. 

      DNA polymerase

    • E. 

      DNA ligase

  • 23. 
    A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
    • A. 

      Continuous translation of the mRNA because of alteration of its structure

    • B. 

      Irreversible binding of the repressor to the operator

    • C. 

      Continuous transcription of the structural gene controlled by that regulator

    • D. 

      Complete inhibition of transcription of the structural gene controlled by that regulator

    • E. 

      Inactivation of RNA polymerase by alteration of its active site

  • 24. 
    During DNA replication,
    • A. 

      Methylated DNA is copied in the cytoplasm, and unmethylated DNA is copied in the nucleus

    • B. 

      Methylation of the DNA is maintained because DNA polymerase directly incorporates methylated nucleotides into the new strand opposite any methylated nucleotides in the template

    • C. 

      DNA polymerase is blocked by methyl groups, and methylated regions of the genome are therefore left uncopied

    • D. 

      All methylation of the DNA is lost at the first round of replication

    • E. 

      Methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication

  • 25. 
    Attenuation occurs in the biosynthetic pathway for phenylalanine in E. coli. Therefore, the leader sequence for this pathway will be rich in which of the following?
    • A. 

      Threonine

    • B. 

      Phenylalanine

    • C. 

      Histidine

    • D. 

      Isoleucine

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