5.12–5.14: Biotechnology is producing improvements in agriculture.

Biotechnology is the use of technology to modify organisms, cells, and their molecules to achieve practical benefits.

Question 5.27

Which of the following statements about mutations is incorrect?

  • a) Mutations are very rare.
  • b) A mutation in DNA always leads to changes in the structure and function of the protein produced.
  • c) When one nucleotide base pair is replaced by another, this constitutes a point mutation.
  • d) One general type of mutation is a change to the overall organization of chromosomal genes.
  • e) X rays can cause mutations.

Question 5.28

Which of the following statements about the metabolism of ethanol (which is present in alcoholic beverages) is incorrect?

  • a) Individuals who produce nonfunctioning aldehyde dehydrogenase exhibit “fast-flushing.”
  • b) The process requires two enzymes: alcohol dehydrogenase and isopropyl dehydrogenase.
  • c) Individuals who are “fast-flushers” are less likely to become alcoholics.
  • d) Aspirin interferes with the action of alcohol dehydrogenase.
  • e) None. All of the statements above are correct.

Question 5.29

The polymerase chain reaction (PCR):

  • a) makes it possible to create huge numbers of copies of tiny pieces of DNA.
  • b) enables researchers to determine the sequence of a complementary strand of DNA when they have only single-stranded DNA.
  • c) utilizes RNA polymerase to build strands of DNA.
  • d) can create messenger RNAmolecules from small pieces of DNA.
  • e) All of the above are correct.

Question 5.30

Which of the following is not a difficulty that medicine has encountered in its attempts to cure human diseases through gene therapy?

  • a) The transfer organism—usually a virus—may get into unintended cells and cause disease.
  • b) It is difficult to get the working gene into the specific cells where it is needed.
  • c) It is difficult to get the working gene into enough cells at the right rate to have a physiological effect.
  • d) For many diseases, a malfunctioning gene has not been identified.
  • e) All of the above are difficulties encountered in attempts to cure human diseases through gene therapy.

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