Bio Test 3 (Part 2)

11 Questions | Total Attempts: 66

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Biology Quizzes & Trivia

Bio test part 2 of 5. 55 question test.


Questions and Answers
  • 1. 
    Repressor proteins
    • A. 

      Prevent binding of RNA polymerase to DNA.

    • B. 

      Cause the DNA regions that contain the operator to twist or loop.

    • C. 

      Inactivate operon genes when their products are not required.

    • D. 

      Bind to sets of operators.

    • E. 

      All of these.

  • 2. 
    The obvious advantage of the lactose operon is that
    • A. 

      It allows bacteria to survive in the presence of lactose.

    • B. 

      Lactose-metabolizing enzymes need not be made when lactose is not present.

    • C. 

      It enables bacteria to make lactose only in the presence of the proper enzymes.

    • D. 

      It negates the need for milk in the diet of adult humans.

    • E. 

      It enables glucose to substitute for lactose in the diet of lactose intolerant persons.

  • 3. 
    Which of the following accounts for the negative control of operons?
    • A. 

      Promoters

    • B. 

      Repressors

    • C. 

      Structural genes

    • D. 

      Operators

    • E. 

      All of these

  • 4. 
    The positive control of the lactose operon in bacteria is
    • A. 

      Activated by a repressor protein.

    • B. 

      Independent of glucose concentration.

    • C. 

      Activated by the CAP.

    • D. 

      Regulated by RNA polymerase.

    • E. 

      All of these.

  • 5. 
    Refer to Figure 15-3 to answer the following questions.As a result of the action illustrated in the figure,
    • A. 

      Structural genes are transcribed.

    • B. 

      Lactose is broken down.

    • C. 

      The lactose operon is repressed.

    • D. 

      The regulatory gene is inactivated.

    • E. 

      Lactose production is enhanced.

  • 6. 
    Lamarck's contribution to the theory of evolution is the concept of
    • A. 

      Natural selection.

    • B. 

      Catastrophism.

    • C. 

      Inheritance of acquired characteristics.

    • D. 

      Mutation.

    • E. 

      Geographic distribution of organisms.

  • 7. 
    Which of the following would be a modern example of Lamarckianism?
    • A. 

      A strain of houseflies resistant to insecticides emerges.

    • B. 

      Squirrels separated by a river are found to be unable to interbreed.

    • C. 

      A son is born with a portion of his right index finger missing, the same portion severed from his father's hand in an accident.

    • D. 

      A strain of houseflies resistant to insecticides emerges; and squirrels separated by a river are found to be unable to interbreed.

    • E. 

      A strain of houseflies resistant to insecticides emerges; and squirrels separated by a river are found to be unable to interbreed; and a son is born with a portion of his right index finger missing, the same portion severed from his father's hand in an accident.

  • 8. 
    Galapagos finches are examples of
    • A. 

      Scavengers.

    • B. 

      Morphological isolation.

    • C. 

      Adaptive radiation.

    • D. 

      Punctuated equilibrium.

    • E. 

      The inheritance of acquired characteristics.

  • 9. 
    Natural selection operates to produce changes in
    • A. 

      Individuals.

    • B. 

      Populations.

    • C. 

      Kingdoms.

    • D. 

      Phyla.

    • E. 

      Animals only.

  • 10. 
    One part of Darwin's theory is that individuals with certain traits have an increased competitive edge. The source of these traits is
    • A. 

      Adaptation to the stress.

    • B. 

      Development over a lifetime.

    • C. 

      Inheritance at conception.

    • D. 

      Mutation after birth.

    • E. 

      All of these.

  • 11. 
    The operation of natural selection depends upon the fact that
    • A. 

      The strong always survive, whereas the weak always die.

    • B. 

      Some individuals have a better chance to produce more offspring.

    • C. 

      Mutations are always harmful.

    • D. 

      Acquired characteristics are inherited.

    • E. 

      Reproduction of all members of a species is virtually the same.

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