Chapter 9
Section 9-1
Vaccine: substance prepared from killed or weakened pathogens (disease-causing agent) and introduced into the body to produce immunity (resistance to a disease)Virulent: able to cause disease
Transformation: the transfer of genetic material from one organism to another, first observed by Griffith.

Avery discovered that DNA is the material responsible fortransformation.
Hershey-Chase experiment: Bacteriophages were used to show that DNA, not protein, is the genetic material of viruses. They conclude that DNA is the molecule that stores genetic information inliving cells.
Bacteriophage: rod-shaped bacterium (viruses that infect bacteria.
Section 9-2
Nucleotide: subunit of nucleic acids consisting of a nitrogenous base, a sugar, and a phosphate groupDeoxyribose: five-carbon sugar that is a component of DNA nucleotides
Chargaff: amounts of A=T and C=G
Franklin and Wilkin: photographs which show the X pattern characteristic of a helix with 2 or 3chains of nucleotides.
Watson and Crick DNA model: taking into account both Chargaff’s findings and Franklin’s and Wilkin’s X-ray diffraction data they built a model of DNA with the configuration of adouble-helix, a “spiral staircase” of nucleotides twisting around a central axis.
Base paring rules: rule stating that in DNA adenine on one strand always pairs with a thymine on the opposite strandand guanine on one strand always pairs with a cytosine on the opposite strand.
Complementary: characteristic of nucleic acids in which the sequence of bases on one strand determines the sequence ofbases on the other.

Section 9-3
DNA Replication: the process of copying DNA, this process produces 2 DNA molecules, each composed of a new and an original strand. The nucleotide sequences in both ofthese DNA molecules are identical to each other and to the original DNA molecule.
DNA Helicase: enzyme that breaks the hydrogen bonds between bases during DNA replication for that the double helix can…