Biology 12

1.Contrast the likely effect of a frameshift
mutation that occurs at the beginning of a gene
with the likely effect of one that occurs near
the end of a gene.

2.One mutagen acts by inserting itself into the
double helix of the DNA molecule, causing the
DNA strand to change its shape. Would this
substance be considered a physical mutagen
or a chemical mutagen? Explain.

3.What is a silent mutation? Explain your answer
in terms of events at the molecular level.

4.Explain how a thymine dimer could arise
within a bacterial cell, and how the cell might
rectify this problem.

5.Complete the following table illustrating four

different types of mutations.

A B

original DNA

(sense strand)

replication

(sense strand)

mRNA

transcribed

amino acid

sequence

TC*TAAG

ATCTAC

C*

changes to

T before

replication

C D

C* lost

during

replication

A inserted

after C*

during

replication

Chapter 9 DNA Mutations and Genetic Engineering • MHR 319

CHAPTER 9 REVIEW

Summary of Expectations

Briefly explain each of the following points.

• All mutations are heritable, but not all
  mutations contribute to genetic variation
  within a species. (9.1)


• A number of factors contribute to the severity
  of a mutation. (9.1)


• The base-pairing properties of DNA are an
  important element in generating recombinant
  DNA. (9.2)


• A restriction endonuclease breaks a DNA
  strand in a predictable fashion. (9.2)


• Gel electrophoresis can be used to generate a
  DNA fingerprint. (9.2)


• The development of heat-resistant DNA
  polymerase has made automated DNA
  amplification much more efficient. (9.2)


• Two different sequencing techniques
  contributed to the results of the Human
  Genome Project. (9.2)


• Expressing a plant gene in a bacterial host
  presents a different set of challenges than
  those posed by expressing a bacterial gene
  in a plant cell host. (9.3)


• Genetically engineered organisms could have
  both positive and negative effects on the
  environment. (9.3)


• It is easier to clone a plant than an animal. (9.4)


• Germ-line therapy raises a number of social
  and ethical issues. (9.4)


• The same characteristics that make a virus
  deadly can make it a good candidate for use
  in gene therapy. (9.4)

Language of Biology

Write a sentence including each of the following

words or terms. Use any six terms in a concept map

to show your understanding of how they are related.

• mutation • chain termination


• germ cell mutation sequencing


• somatic cell mutation • dideoxynucleotide


• point mutation • bacterial artificial


• silent mutation chromosome (BAC)


• mis-sense mutation • BAC-to-BAC


• nonsense mutation sequencing


• frameshift mutation • whole genome shotgun


• spontaneous mutation sequencing


• induced • Human Genome


• mutagen Project (HGP)


• physical mutagen • somatotropin


• chemical mutagen • transgenic


• Ames test • nucleic acid hybridization


• reverse mutation • expression vector


• carcinogenic • reverse transcriptase


• direct repair • copy DNA (cDNA)


• excision repair • Ti plasmid


• recombination repair • DNA particle gun


• restriction endonucleases • bioremediation


• restriction site • differentiation


• restriction fragments • therapeutic cloning


• sticky ends • reproductive cloning


• recombinant DNA • gene therapy


• DNA amplification •ex vivotherapy


• cloning vector •in situtherapy


• polymerase chain •in vivotherapy
  reaction (PCR) • somatic gene therapy


• gel electrophoresis • germ-line therapy


• DNA fingerprint

UNDERSTANDING CONCEPTS